From blaktony86 at yahoo.com  Sat May  2 00:31:19 2009
From: blaktony86 at yahoo.com (TONY B)
Date: Fri, 01 May 2009 10:31:19 CDT
Subject: [ATM] Working with thin mirrors
Message-ID: <mailman.247.1241191883.7676.atm@atmlist.net>

Hello, i havent been on the atm list in a while. I started my first mirror at age 14 and after growing up (i am 23 now), I finally found time to complete my third mirror, a 9.2" full thickness F/6. I am in the final figuring stage and i am excited to be making telescope mirrors again. I had to order some pitch because mine was 7 years old and used many times. I ordered it from gotgrit and saw they had thin plate glass mirrors for sale. Have any of you guys had experience grinding these 3/4" blanks? I was thinking of doing a 14" mirror. Would a 16" mirror be asking for trouble? I am ready for a challenge and would love a large, fast mirror. Thanks guys and its good to be back. Also thanks to mel bartels and frank ward for helping me in the past, those two people i believed sent me items to help me in my past projects, in which i will always be grateful. -Tony Blakesley


From blaktony86 at yahoo.com  Sat May  2 00:39:35 2009
From: blaktony86 at yahoo.com (TONY BLAKESLEY)
Date: Fri, 1 May 2009 08:39:35 -0700 (PDT)
Subject: [ATM] Making Thin mirrors
Message-ID: <246496.91965.qm@web81908.mail.mud.yahoo.com>

Hello,
?
I havent been on the ATM list in quite a while. I was 14 years old when I first joined the atm list and made my first mirror (a 6"). I am now 22 years old (had to do some growing up) and finally have gotten back into making telescope mirrors again. I am on my 3rd mirror, a 9.2" full thickness pyrex. Its an F/6 and I am in the final stages of figuring. Its amazing how much is coming back to me after doing some Ronchi testing. I am very excited to get back into telescope making again. The mirror is going to be housed in a Truss style dobsonian that my dad and I made together out of Walnut and its beautiful. I will have to create a website for you guys to see it. 
?
I had to order some new pitch at gotgrit.com because my pitch was over 7 years old and used many times (risking contamination) so I went and ordered some. I saw they had plate glass mirrors at got grit in 3/4" thickness. Would it be crazy for me to do a 14 or 16" in this thickness? I would prefer about an F/4 to F/5. 
?
I would also like to extend my thanks and gratitude to Mel Bartels and Frank Ward, who I believe actually sent me items to help me in my telescope making interests when I was a teenager. Also to everyone on the list for all the great information!
?
-Tony Blakesley

From astroguy at nas.com  Sat May  2 02:12:54 2009
From: astroguy at nas.com (kreig)
Date: Fri, 1 May 2009 10:12:54 -0700
Subject: [ATM] Working with thin mirrors
References: <mailman.247.1241191883.7676.atm@atmlist.net>
Message-ID: <005f01c9ca80$139f9560$e64dfb48@LILBERT>

Tony,

You are very lucky to have grown up at the age of 23.  I am 60 this year and 
still have not grown up, life is soooooo short.  :-)

The "thinner" a glass blank becomes the more difficulties can occur.  what 
you need to decide is the purpose to work on a  thin mirror.  For the 
challenge, portability, thermal equilibrium, etc.  As with any choice there 
are plusses and minuses.

Do you only want to make mirrors or do you have specific sky goals?  what 
depth of deep sky might you want to reach?  This might better answer your 
question about aperture size.

There have been some rather large thin mirrors produced by atms, much larger 
than you propose, I think you will do well with either 14" or 16".

Kreig



----- Original Message ----- 
From: "TONY B" <blaktony86 at yahoo.com>
To: <atm at atmlist.net>
Sent: Friday, May 01, 2009 8:31 AM
Subject: [ATM] Working with thin mirrors


> Hello, i havent been on the atm list in a while. I started my first mirror 
> at age 14 and after growing up (i am 23 now), I finally found time to 
> complete my third mirror, a 9.2" full thickness F/6. I am in the final 
> figuring stage and i am excited to be making telescope mirrors again. I 
> had to order some pitch because mine was 7 years old and used many times. 
> I ordered it from gotgrit and saw they had thin plate glass mirrors for 
> sale. Have any of you guys had experience grinding these 3/4" blanks? I 
> was thinking of doing a 14" mirror. Would a 16" mirror be asking for 
> trouble? I am ready for a challenge and would love a large, fast mirror. 
> Thanks guys and its good to be back. Also thanks to mel bartels and frank 
> ward for helping me in the past, those two people i believed sent me items 
> to help me in my past projects, in which i will always be grateful. -Tony 
> Blakesley
>
> _______________________________________________
> ATM mailing list http://www.atmlist.net/
>
>
>
> -- 
> Internal Virus Database is out-of-date.
> Checked by AVG Free Edition.
> Version: 7.1.413 / Virus Database: 268.18.23/740 - Release Date: 3/30/2007
>
> 


From blaktony86 at yahoo.com  Sat May  2 03:36:35 2009
From: blaktony86 at yahoo.com (TONY BLAKESLEY)
Date: Fri, 1 May 2009 11:36:35 -0700 (PDT)
Subject: [ATM] Working with thin mirrors
In-Reply-To: <005f01c9ca80$139f9560$e64dfb48@LILBERT>
Message-ID: <589802.85114.qm@web81905.mail.mud.yahoo.com>

Well, grown up in the fact that I support myself now. Oh and sorry for the double post. I thought the first message didnt go through.
?
Anyone with personal experiences/challenges with thin mirrors of this size?
?
Thanks,
?
Tony

--- On Fri, 5/1/09, kreig <astroguy at nas.com> wrote:

From: kreig <astroguy at nas.com>
Subject: Re: [ATM] Working with thin mirrors
To: "TONY B" <blaktony86 at yahoo.com>, atm at atmlist.net
Date: Friday, May 1, 2009, 12:12 PM

Tony,

You are very lucky to have grown up at the age of 23.  I am 60 this year and
still have not grown up, life is soooooo short.  :-)

The "thinner" a glass blank becomes the more difficulties can occur. 
what you need to decide is the purpose to work on a  thin mirror.  For the
challenge, portability, thermal equilibrium, etc.  As with any choice there are
plusses and minuses.

Do you only want to make mirrors or do you have specific sky goals?  what depth
of deep sky might you want to reach?  This might better answer your question
about aperture size.

There have been some rather large thin mirrors produced by atms, much larger
than you propose, I think you will do well with either 14" or 16".

Kreig



----- Original Message ----- From: "TONY B"
<blaktony86 at yahoo.com>
To: <atm at atmlist.net>
Sent: Friday, May 01, 2009 8:31 AM
Subject: [ATM] Working with thin mirrors


> Hello, i havent been on the atm list in a while. I started my first mirror
at age 14 and after growing up (i am 23 now), I finally found time to complete
my third mirror, a 9.2" full thickness F/6. I am in the final figuring
stage and i am excited to be making telescope mirrors again. I had to order some
pitch because mine was 7 years old and used many times. I ordered it from
gotgrit and saw they had thin plate glass mirrors for sale. Have any of you guys
had experience grinding these 3/4" blanks? I was thinking of doing a
14" mirror. Would a 16" mirror be asking for trouble? I am ready for a
challenge and would love a large, fast mirror. Thanks guys and its good to be
back. Also thanks to mel bartels and frank ward for helping me in the past,
those two people i believed sent me items to help me in my past projects, in
which i will always be grateful. -Tony Blakesley
> 
> _______________________________________________
> ATM mailing list http://www.atmlist.net/
> 
> 
> 
> -- Internal Virus Database is out-of-date.
> Checked by AVG Free Edition.
> Version: 7.1.413 / Virus Database: 268.18.23/740 - Release Date: 3/30/2007
> 
> 


From blaktony86 at yahoo.com  Sat May  2 03:59:13 2009
From: blaktony86 at yahoo.com (TONY BLAKESLEY)
Date: Fri, 1 May 2009 11:59:13 -0700 (PDT)
Subject: [ATM] Working with thin mirrors
In-Reply-To: <589802.85114.qm@web81905.mail.mud.yahoo.com>
Message-ID: <566476.16564.qm@web81905.mail.mud.yahoo.com>

Oh and my goals are:
?
Enough aperture to see faint deep sky objects such as galaxies but also fast enough and a large viewing field to see larger objects such as nebulae. 
?
Is it possible to see color in nebula with a 14" or 16" telescope? That would be impressive as I have never seen color in deep sky objects before.
?


--- On Fri, 5/1/09, TONY BLAKESLEY <blaktony86 at yahoo.com> wrote:

From: TONY BLAKESLEY <blaktony86 at yahoo.com>
Subject: Re: [ATM] Working with thin mirrors
To: "kreig" <astroguy at nas.com>, atm at atmlist.net
Date: Friday, May 1, 2009, 1:36 PM

Well, grown up in the fact that I support myself now. Oh and sorry for the
double post. I thought the first message didnt go through.
?
Anyone with personal experiences/challenges with thin mirrors of this size?
?
Thanks,
?
Tony

--- On Fri, 5/1/09, kreig <astroguy at nas.com> wrote:

From: kreig <astroguy at nas.com>
Subject: Re: [ATM] Working with thin mirrors
To: "TONY B" <blaktony86 at yahoo.com>, atm at atmlist.net
Date: Friday, May 1, 2009, 12:12 PM

Tony,

You are very lucky to have grown up at the age of 23.  I am 60 this year and
still have not grown up, life is soooooo short.  :-)

The "thinner" a glass blank becomes the more difficulties can occur. 
what you need to decide is the purpose to work on a  thin mirror.  For the
challenge, portability, thermal equilibrium, etc.  As with any choice there are
plusses and minuses.

Do you only want to make mirrors or do you have specific sky goals?  what depth
of deep sky might you want to reach?  This might better answer your question
about aperture size.

There have been some rather large thin mirrors produced by atms, much larger
than you propose, I think you will do well with either 14" or 16".

Kreig



----- Original Message ----- From: "TONY B"
<blaktony86 at yahoo.com>
To: <atm at atmlist.net>
Sent: Friday, May 01, 2009 8:31 AM
Subject: [ATM] Working with thin mirrors


> Hello, i havent been on the atm list in a while. I started my first mirror
at age 14 and after growing up (i am 23 now), I finally found time to complete
my third mirror, a 9.2" full thickness F/6. I am in the final figuring
stage and i am excited to be making telescope mirrors again. I had to order
some
pitch because mine was 7 years old and used many times. I ordered it from
gotgrit and saw they had thin plate glass mirrors for sale. Have any of you
guys
had experience grinding these 3/4" blanks? I was thinking of doing a
14" mirror. Would a 16" mirror be asking for trouble? I am ready for
a
challenge and would love a large, fast mirror. Thanks guys and its good to be
back. Also thanks to mel bartels and frank ward for helping me in the past,
those two people i believed sent me items to help me in my past projects, in
which i will always be grateful. -Tony Blakesley
> 
> _______________________________________________
> ATM mailing list http://www.atmlist.net/
> 
> 
> 
> -- Internal Virus Database is out-of-date.
> Checked by AVG Free Edition.
> Version: 7.1.413 / Virus Database: 268.18.23/740 - Release Date: 3/30/2007
> 
> 

_______________________________________________
ATM mailing list http://www.atmlist.net/

From rmay at nethere.com  Sat May  2 05:30:12 2009
From: rmay at nethere.com (Bob May)
Date: Fri, 1 May 2009 13:30:12 -0700
Subject: [ATM] Working with thin mirrors
References: <mailman.247.1241191883.7676.atm@atmlist.net>
Message-ID: <001401c9ca9b$a1dc97e0$8f78fea9@amd>

I've got one grinder that is working on a 17" F4.5 mirror right
now.
Things are flexible at that thickness so you have to take care to
support the mirror when grinding and polishing so that it doesn't
flex too much.  Final grinding should be done with the mirror on
top with a full sized tool.  Don't go flipping the mirror/tool in
the last two grit sizes or you will end up with a hyperbolic
surface from that.
When doing the polishing, turn the mirror on the supports
FREQUENTLY!  Every minute at the least and astigmatism will be
minimal.  This size mirror is about the largest that you can
really do with the mirror on top of a full sized lap as the
friction gets really heavy at this size.
I'll also note that another guy is doing a Lurie-Houghton 12"
scope and the two lenses that are on the front end of that scope
are 3/4" at their thickest and  failure to turn the lenses on the
support tended to make about 3 waves of astig. in curvature in
about 5 minutes.  Bending just from the weight of the lens can
make a 1.5 wave error in the glass.  What this means is that when
you test the glass for shape, make sure that you've got the
mirror in a good cell or you WILL be seeing errors from bending
of the glass!
Other than that, good luck!
Bob May

rmay at nethere.com
http: slash /nav.to slash bobmay
http: slash /bobmay dot astronomy.net



From atmpob at yahoo.com  Sat May  2 05:58:45 2009
From: atmpob at yahoo.com (Dale Eason)
Date: Fri, 1 May 2009 13:58:45 -0700 (PDT)
Subject: [ATM] Working with thin mirrors
In-Reply-To: <566476.16564.qm@web81905.mail.mud.yahoo.com>
Message-ID: <542942.93754.qm@web54502.mail.re2.yahoo.com>


In my experience it is not possible to see much color even in a 16.

At to galaxies, here it becomes a bit relative and dependant on your sky condition.  Even a small scope can see Andromada but just as a fuzzy blob.  8 inchers can see a few smaller galaxies but mostly as fuzzy objects.  A 16 inch in good dark skies can see a couple dark lanes in Andromada.  The spiral structure of M51 shows up better in a 20 incher and above.  Dobson states in his video that you really need 16 or larger to see interesting stuff but I'm sure others may have other views.  I have seen great views of the Veil at a dark site and Ring in a good  8 and 10 inch.


Dale Eason

--- On Fri, 5/1/09, TONY BLAKESLEY <blaktony86 at yahoo.com> wrote:

> From: TONY BLAKESLEY <blaktony86 at yahoo.com>
> Subject: Re: [ATM] Working with thin mirrors
> To: astroguy at nas.com, atm at atmlist.net
> Date: Friday, May 1, 2009, 1:59 PM
> Oh and my goals are:
> ?
> Enough aperture to see faint deep sky objects such as
> galaxies but also fast enough and a large viewing field to
> see larger objects such as nebulae. 
> ?
> Is it possible to see color in nebula with a 14" or
> 16" telescope? That would be impressive as I have never
> seen color in deep sky objects before.
> ?
> 
> 
> --- On Fri, 5/1/09, TONY BLAKESLEY
> <blaktony86 at yahoo.com> wrote:
> 
> From: TONY BLAKESLEY <blaktony86 at yahoo.com>
> Subject: Re: [ATM] Working with thin mirrors
> To: "kreig" <astroguy at nas.com>,
> atm at atmlist.net
> Date: Friday, May 1, 2009, 1:36 PM
> 
> Well, grown up in the fact that I support myself now. Oh
> and sorry for the
> double post. I thought the first message didnt go through.
> ?
> Anyone with personal experiences/challenges with thin
> mirrors of this size?
> ?
> Thanks,
> ?
> Tony
> 
> --- On Fri, 5/1/09, kreig <astroguy at nas.com> wrote:
> 
> From: kreig <astroguy at nas.com>
> Subject: Re: [ATM] Working with thin mirrors
> To: "TONY B" <blaktony86 at yahoo.com>,
> atm at atmlist.net
> Date: Friday, May 1, 2009, 12:12 PM
> 
> Tony,
> 
> You are very lucky to have grown up at the age of 23.  I am
> 60 this year and
> still have not grown up, life is soooooo short.  :-)
> 
> The "thinner" a glass blank becomes the more
> difficulties can occur. 
> what you need to decide is the purpose to work on a  thin
> mirror.  For the
> challenge, portability, thermal equilibrium, etc.  As with
> any choice there are
> plusses and minuses.
> 
> Do you only want to make mirrors or do you have specific
> sky goals?  what depth
> of deep sky might you want to reach?  This might better
> answer your question
> about aperture size.
> 
> There have been some rather large thin mirrors produced by
> atms, much larger
> than you propose, I think you will do well with either
> 14" or 16".
> 
> Kreig
> 
> 
> 
> ----- Original Message ----- From: "TONY B"
> <blaktony86 at yahoo.com>
> To: <atm at atmlist.net>
> Sent: Friday, May 01, 2009 8:31 AM
> Subject: [ATM] Working with thin mirrors
> 
> 
> > Hello, i havent been on the atm list in a while. I
> started my first mirror
> at age 14 and after growing up (i am 23 now), I finally
> found time to complete
> my third mirror, a 9.2" full thickness F/6. I am in
> the final figuring
> stage and i am excited to be making telescope mirrors
> again. I had to order
> some
> pitch because mine was 7 years old and used many times. I
> ordered it from
> gotgrit and saw they had thin plate glass mirrors for sale.
> Have any of you
> guys
> had experience grinding these 3/4" blanks? I was
> thinking of doing a
> 14" mirror. Would a 16" mirror be asking for
> trouble? I am ready for
> a
> challenge and would love a large, fast mirror. Thanks guys
> and its good to be
> back. Also thanks to mel bartels and frank ward for helping
> me in the past,
> those two people i believed sent me items to help me in my
> past projects, in
> which i will always be grateful. -Tony Blakesley
> > 
> > _______________________________________________
> > ATM mailing list http://www.atmlist.net/
> > 
> > 
> > 
> > -- Internal Virus Database is out-of-date.
> > Checked by AVG Free Edition.
> > Version: 7.1.413 / Virus Database: 268.18.23/740 -
> Release Date: 3/30/2007
> > 
> > 
> 
> _______________________________________________
> ATM mailing list http://www.atmlist.net/
> _______________________________________________
> ATM mailing list http://www.atmlist.net/


      

From blaktony86 at yahoo.com  Sat May  2 06:21:45 2009
From: blaktony86 at yahoo.com (TONY B)
Date: Fri, 01 May 2009 16:21:45 CDT
Subject: [ATM] Working with thin mirrors
Message-ID: <mailman.269.1241212909.7676.atm@atmlist.net>

  ok, great. I guess the bigger the better right? After i finish my 9" i will step it up to a 16"... Im excited. Anyone order the blanks from gotgrit?
-----Original Message-----
Date: Friday, May 01, 2009 3:59:42 pm
To: atm at atmlist.net
From: "Dale Eason" <atmpob at yahoo.com>
Subject: Re: [ATM] Working with thin mirrors


In my experience it is not possible to see much color even in a 16.

At to galaxies, here it becomes a bit relative and dependant on your sky condition.  Even a small scope can see Andromada but just as a fuzzy blob.  8 inchers can see a few smaller galaxies but mostly as fuzzy objects.  A 16 inch in good dark skies can see a couple dark lanes in Andromada.  The spiral structure of M51 shows up better in a 20 incher and above.  Dobson states in his video that you really need 16 or larger to see interesting stuff but I'm sure others may have other views.  I have seen great views of the Veil at a dark site and Ring in a good  8 and 10 inch.


Dale Eason

--- On Fri, 5/1/09, TONY BLAKESLEY <blaktony86 at yahoo.com> wrote:

> From: TONY BLAKESLEY <blaktony86 at yahoo.com>
> Subject: Re: [ATM] Working with thin mirrors
> To: astroguy at nas.com, atm at atmlist.net
> Date: Friday, May 1, 2009, 1:59 PM
> Oh and my goals are:
> ?
> Enough aperture to see faint deep sky objects such as
> galaxies but also fast e


From mbartels at bbastrodesigns.com  Sat May  2 10:02:42 2009
From: mbartels at bbastrodesigns.com (Mel Bartels)
Date: Fri, 1 May 2009 18:02:42 -0700
Subject: [ATM] Working with thin mirrors
In-Reply-To: <542942.93754.qm@web54502.mail.re2.yahoo.com>
References: <566476.16564.qm@web81905.mail.mud.yahoo.com>
	<542942.93754.qm@web54502.mail.re2.yahoo.com>
Message-ID: <001e01c9cac1$b7b681e0$272385a0$@com>

> Oh and my goals are:
> ?
> Enough aperture to see faint deep sky objects such as
> galaxies but also fast enough and a large viewing field to
> see larger objects such as nebulae. 
> ?
> Is it possible to see color in nebula with a 14" or
> 16" telescope? That would be impressive as I have never
> seen color in deep sky objects before.



>From the optimum detection magnification graphs, it appears that 16 inches
of aperture is at the tradeoff point.  Diminishing returns set in for larger
apertures.  Of course, for those objects not visible in a 16 inch scope...
http://www.bbastrodesigns.com/dnld/odm.zip 

This could be the basis for so many scopes being 16 inches in aperture.
Witness last year's Oregon Star Party Walkabout where the average scope size
was a 16 inch.  http://www.bbastrodesigns.com/osp08/osp08walkabout.html 

Color is illusive in 40 inch scopes.

Mel Bartels



From foreilly at verizon.net  Sat May  2 18:21:16 2009
From: foreilly at verizon.net (Francis J. O'Reilly)
Date: Sat, 02 May 2009 05:21:16 -0400
Subject: [ATM] Got Grit
References: <mailman.269.1241212909.7676.atm@atmlist.net>
Message-ID: <22ED4E46CEC0400BBFE0F9B0A03143DD@HELENYLCMWAV95>

Tony,

Tom Mouton, who owns Got Grit is on the list, why don't you ask him 
directly? He is very responsive.

I have made several purchases from Tom. Never a problem. Tom delivers what 
he says he can deliver. For larger quantities of grit and different types of 
rare earth polishing compounds, I have purchased from Universal Photonics on 
Lon guy land. Newport Glass in California has some great prices on various 
types of glass including large thin blanks (Although I for one prefer blanks 
with a 1:6 thickness to diameter ratio)

Good luck and welcome back to the community of telescope makers.

Francis J. O'Reilly
----- Original Message ----- 
From: "TONY B" <blaktony86 at yahoo.com>
To: <atm at atmlist.net>
Sent: Friday, May 01, 2009 5:21 PM
Subject: Re: [ATM] Working with thin mirrors


  ok, great. I guess the bigger the better right? After i finish my 9" i 
will step it up to a 16"... Im excited. Anyone order the blanks from 
gotgrit?
-----Original Message-----
Date: Friday, May 01, 2009 3:59:42 pm
To: atm at atmlist.net
From: "Dale Eason" <atmpob at yahoo.com>
Subject: Re: [ATM] Working with thin mirrors


In my experience it is not possible to see much color even in a 16.

At to galaxies, here it becomes a bit relative and dependant on your sky 
condition.  Even a small scope can see Andromada but just as a fuzzy blob. 
8 inchers can see a few smaller galaxies but mostly as fuzzy objects.  A 16 
inch in good dark skies can see a couple dark lanes in Andromada.  The 
spiral structure of M51 shows up better in a 20 incher and above.  Dobson 
states in his video that you really need 16 or larger to see interesting 
stuff but I'm sure others may have other views.  I have seen great views of 
the Veil at a dark site and Ring in a good  8 and 10 inch.


Dale Eason

--- On Fri, 5/1/09, TONY BLAKESLEY <blaktony86 at yahoo.com> wrote:

> From: TONY BLAKESLEY <blaktony86 at yahoo.com>
> Subject: Re: [ATM] Working with thin mirrors
> To: astroguy at nas.com, atm at atmlist.net
> Date: Friday, May 1, 2009, 1:59 PM
> Oh and my goals are:
>
> Enough aperture to see faint deep sky objects such as
> galaxies but also fast e

_______________________________________________
ATM mailing list http://www.atmlist.net/ 


From rmay at nethere.com  Sun May  3 11:36:57 2009
From: rmay at nethere.com (Bob May)
Date: Sat, 2 May 2009 19:36:57 -0700
Subject: [ATM] Got Grit
References: <mailman.269.1241212909.7676.atm@atmlist.net>
	<22ED4E46CEC0400BBFE0F9B0A03143DD@HELENYLCMWAV95>
Message-ID: <000201c9cb98$3c0ca920$8f78fea9@amd>

The problem with asking the owner of a business is that he is
extremely biased.  Sad fact but unfortunately true.  He could be
truthful or a not so truthful person and the buyer really won't
know.
His glass is decently good glass (it ain't optical pyrex that you
can look through) but for mirrors, you don't need Grade A glass
free of bubbles and so forth that you need for lenses.  I've not
heard anywhere that there have been any troubles with his grit,
pitch (he merely resells the manufacturer's packaging on this) or
glass or even the kits for doing all of the work.
He also has a great website.
Bob May

rmay at nethere.com
http: slash /nav.to slash bobmay
http: slash /bobmay dot astronomy.net



From pdebaan at hotmail.com  Sun May  3 13:32:29 2009
From: pdebaan at hotmail.com (Peter De Baan)
Date: Sun, 3 May 2009 04:32:29 +0000
Subject: [ATM] Working with thin mirrors
In-Reply-To: <001e01c9cac1$b7b681e0$272385a0$@com>
References: <566476.16564.qm@web81905.mail.mud.yahoo.com>
	<542942.93754.qm@web54502.mail.re2.yahoo.com> 
	<001e01c9cac1$b7b681e0$272385a0$@com>
Message-ID: <BLU137-W1001416C8272364838B929B26B0@phx.gbl>


I believe that very few people have directly, that is with a telescope, seen much colors in the nighttime sky, because of our limited color vision capacety at nighttime.

 ("all cats become grey in the dark") regardles of the telescope size, therefore photography is ideal for being able the see night-time color views in daylight, and many people have even then difficulty because of slight color blindness, and good color pictures can be made in small aperture telescopes.

 

Peter

 

 
> From: mbartels at bbastrodesigns.com
> To: atm at atmlist.net
> Date: Fri, 1 May 2009 18:02:42 -0700
> Subject: Re: [ATM] Working with thin mirrors
> 
> > Oh and my goals are:
> >  
> > Enough aperture to see faint deep sky objects such as
> > galaxies but also fast enough and a large viewing field to
> > see larger objects such as nebulae. 
> >  
> > Is it possible to see color in nebula with a 14" or
> > 16" telescope? That would be impressive as I have never
> > seen color in deep sky objects before.
> 
> 
> 
> >From the optimum detection magnification graphs, it appears that 16 inches
> of aperture is at the tradeoff point. Diminishing returns set in for larger
> apertures. Of course, for those objects not visible in a 16 inch scope...
> http://www.bbastrodesigns.com/dnld/odm.zip 
> 
> This could be the basis for so many scopes being 16 inches in aperture.
> Witness last year's Oregon Star Party Walkabout where the average scope size
> was a 16 inch. http://www.bbastrodesigns.com/osp08/osp08walkabout.html 
> 
> Color is illusive in 40 inch scopes.
> 
> Mel Bartels

> _______________________________________________
> ATM mailing list http://www.atmlist.net/

_________________________________________________________________
Insert movie times and more without leaving Hotmail?.
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From mirceapte at yahoo.com  Sun May  3 22:54:36 2009
From: mirceapte at yahoo.com (Mircea Pteancu)
Date: Sun, 3 May 2009 06:54:36 -0700 (PDT)
Subject: [ATM] Working with thin mirrors
Message-ID: <798952.442.qm@web35803.mail.mud.yahoo.com>

I hope? I will not upset anybody, I'm age 54 but I'm a small guy compared to you.My telescope is a small Dobsonian of 125mm F/7 but for me the sky is full of colour.Planetary discs are in strong dominant colours?with subtle hues and?tints,this is why since ancient times they was associated with metals.?And the stars have many different colours,particularly visible at double star or large rezolved open cluster observations.Deep-Sky objects not so,but in M42, at least, I saw three colours.Not speaking about the Moon,what a beauty, or the colours of ?bright comets or of the rare fireballs.Maybe it is something wrong with me or my equipment,the most complex eyepieces I'm using?are Erfles.Regards,Mircea

--- On Sun, 5/3/09, Peter De Baan <pdebaan at hotmail.com> wrote:


From: Peter De Baan <pdebaan at hotmail.com>
Subject: Re: [ATM] Working with thin mirrors
To: "Mel Bartels" <mbartels at bbastrodesigns.com>, atm at atmlist.net
Date: Sunday, May 3, 2009, 7:32 AM



I believe that very few people have directly, that is with a telescope, seen much colors in the nighttime sky, because of our limited color vision capacety at nighttime.

("all cats become grey in the dark") regardles of the telescope size, therefore photography is ideal for being able the see night-time color views in daylight, and many people have even then difficulty because of slight color blindness, and good color pictures can be made in small aperture telescopes.



Peter




> From: mbartels at bbastrodesigns.com
> To: atm at atmlist.net
> Date: Fri, 1 May 2009 18:02:42 -0700
> Subject: Re: [ATM] Working with thin mirrors
> 
> > Oh and my goals are:
> >? 
> > Enough aperture to see faint deep sky objects such as
> > galaxies but also fast enough and a large viewing field to
> > see larger objects such as nebulae. 
> >? 
> > Is it possible to see color in nebula with a 14" or
> > 16" telescope? That would be impressive as I have never
> > seen color in deep sky objects before.
> 
> 
> 
> >From the optimum detection magnification graphs, it appears that 16 inches
> of aperture is at the tradeoff point. Diminishing returns set in for larger
> apertures. Of course, for those objects not visible in a 16 inch scope...
> http://www.bbastrodesigns.com/dnld/odm.zip 
> 
> This could be the basis for so many scopes being 16 inches in aperture.
> Witness last year's Oregon Star Party Walkabout where the average scope size
> was a 16 inch. http://www.bbastrodesigns.com/osp08/osp08walkabout.html 
> 
> Color is illusive in 40 inch scopes.
> 
> Mel Bartels

> _______________________________________________
> ATM mailing list http://www.atmlist.net/

_________________________________________________________________
Insert movie times and more without leaving Hotmail?.
http://windowslive.com/Tutorial/Hotmail/QuickAdd?ocid=TXT_TAGLM_WL_HM_Tutorial_QuickAdd1_052009
_______________________________________________
ATM mailing list http://www.atmlist.net/



      

From gilboastro at yahoo.com  Mon May  4 00:50:19 2009
From: gilboastro at yahoo.com (Gil McFarlane)
Date: Sun, 3 May 2009 08:50:19 -0700 (PDT)
Subject: [ATM] seeing color (was thin mirrors)
In-Reply-To: <798952.442.qm@web35803.mail.mud.yahoo.com>
Message-ID: <440445.59184.qm@web62102.mail.re1.yahoo.com>


I think this brings up a very interesting point.

Seeing anything requires training of the brain - there is a lot of psychological research on that topic.  But consider how photographers know that normal fluorescent tubes actually emit a green light, and regular bulbs emit a red light, but since we "know" what color things are in a room, we do not see the lights as colored.  We see the white wall as white.  After a few years of taking pictures I found I could see the color of the light and make appropriate filter choices - but it took some training.

I suspect the same would be true with nigh-time objects.  If we look at them casually and do not expect to see color, we will not likely see them.  I suspect it would be possible to train ourselves to see the subtle color that is there.

Plus, it sounds like fun (of a subtle kind.)

- Gil
Ventura


--- On Sun, 5/3/09, Mircea Pteancu <mirceapte at yahoo.com> wrote:

> From: Mircea Pteancu <mirceapte at yahoo.com>
> Subject: Re: [ATM] Working with thin mirrors
> To: "Peter De Baan" <pdebaan at hotmail.com>, atm at atmlist.net
> Date: Sunday, May 3, 2009, 6:54 AM
> I hope? I will not upset anybody, I'm age 54 but
> I'm a small guy compared to you.My telescope is a small
> Dobsonian of 125mm F/7 but for me the sky is full of
> colour.Planetary discs are in strong dominant colours?with
> subtle hues and?tints,this is why since ancient times they
> was associated with metals.?And the stars have many
> different colours,particularly visible at double star or
> large rezolved open cluster observations.Deep-Sky objects
> not so,but in M42, at least, I saw three colours.Not
> speaking about the Moon,what a beauty, or the colours of
> ?bright comets or of the rare fireballs.Maybe it is
> something wrong with me or my equipment,the most complex
> eyepieces I'm using?are Erfles.Regards,Mircea
> 
> --- On Sun, 5/3/09, Peter De Baan
> <pdebaan at hotmail.com> wrote:
> 
> 
> From: Peter De Baan <pdebaan at hotmail.com>
> Subject: Re: [ATM] Working with thin mirrors
> To: "Mel Bartels"
> <mbartels at bbastrodesigns.com>, atm at atmlist.net
> Date: Sunday, May 3, 2009, 7:32 AM
> 
> 
> 
> I believe that very few people have directly, that is with
> a telescope, seen much colors in the nighttime sky, because
> of our limited color vision capacety at nighttime.
> 
> ("all cats become grey in the dark") regardles of
> the telescope size, therefore photography is ideal for being
> able the see night-time color views in daylight, and many
> people have even then difficulty because of slight color
> blindness, and good color pictures can be made in small
> aperture telescopes.
> 
> 
> 
> Peter
> 
> 
> 
> 
> > From: mbartels at bbastrodesigns.com
> > To: atm at atmlist.net
> > Date: Fri, 1 May 2009 18:02:42 -0700
> > Subject: Re: [ATM] Working with thin mirrors
> > 
> > > Oh and my goals are:
> > >? 
> > > Enough aperture to see faint deep sky objects
> such as
> > > galaxies but also fast enough and a large viewing
> field to
> > > see larger objects such as nebulae. 
> > >? 
> > > Is it possible to see color in nebula with a
> 14" or
> > > 16" telescope? That would be impressive as I
> have never
> > > seen color in deep sky objects before.
> > 
> > 
> > 
> > >From the optimum detection magnification graphs,
> it appears that 16 inches
> > of aperture is at the tradeoff point. Diminishing
> returns set in for larger
> > apertures. Of course, for those objects not visible in
> a 16 inch scope...
> > http://www.bbastrodesigns.com/dnld/odm.zip 
> > 
> > This could be the basis for so many scopes being 16
> inches in aperture.
> > Witness last year's Oregon Star Party Walkabout
> where the average scope size
> > was a 16 inch.
> http://www.bbastrodesigns.com/osp08/osp08walkabout.html 
> > 
> > Color is illusive in 40 inch scopes.
> > 
> > Mel Bartels
> 
> > _______________________________________________
> > ATM mailing list http://www.atmlist.net/
> 
> _________________________________________________________________
> Insert movie times and more without leaving Hotmail?.
> http://windowslive.com/Tutorial/Hotmail/QuickAdd?ocid=TXT_TAGLM_WL_HM_Tutorial_QuickAdd1_052009
> _______________________________________________
> ATM mailing list http://www.atmlist.net/
> 
> 
> 
>       
> _______________________________________________
> ATM mailing list http://www.atmlist.net/


      

From jkoptic at juno.com  Mon May  4 03:22:30 2009
From: jkoptic at juno.com (Jarvis Krumbein)
Date: Sun, 3 May 2009 11:22:30 -0700
Subject: [ATM] Working with thin mirrors
Message-ID: <20090503.112230.3572.0.jkoptic@juno.com>

I think everyone is overlooking the difference in sensitivity of the eye
between the rods and cones.  much higher light levels are required to
activate the color sensors.  Diffuse objects, with rare exception, have
very low average light levels while stellar and planetary objects are
much more concentrated and therefore have much higher light levels thus
color can be seen.

Jarvis Krumbein

On Sun, 3 May 2009 06:54:36 -0700 (PDT) Mircea Pteancu
<mirceapte at yahoo.com> writes:
> I hope? I will not upset anybody, I'm age 54 but I'm a small guy 
> compared to you.My telescope is a small Dobsonian of 125mm F/7 but 
> for me the sky is full of colour.Planetary discs are in strong 
> dominant colours?with subtle hues and?tints,this is why since 
> ancient times they was associated with metals.?And the stars have 
> many different colours,particularly visible at double star or large 
> rezolved open cluster observations.Deep-Sky objects not so,but in 
> M42, at least, I saw three colours.Not speaking about the Moon,what 
> a beauty, or the colours of ?bright comets or of the rare 
> fireballs.Maybe it is something wrong with me or my equipment,the 
> most complex eyepieces I'm using?are Erfles.Regards,Mircea
> 
> --- On Sun, 5/3/09, Peter De Baan <pdebaan at hotmail.com> wrote:
> 
> 
> From: Peter De Baan <pdebaan at hotmail.com>
> Subject: Re: [ATM] Working with thin mirrors
> To: "Mel Bartels" <mbartels at bbastrodesigns.com>, atm at atmlist.net
> Date: Sunday, May 3, 2009, 7:32 AM
> 
> 
> 
> I believe that very few people have directly, that is with a 
> telescope, seen much colors in the nighttime sky, because of our 
> limited color vision capacety at nighttime.
> 
> ("all cats become grey in the dark") regardles of the telescope 
> size, therefore photography is ideal for being able the see 
> night-time color views in daylight, and many people have even then 
> difficulty because of slight color blindness, and good color 
> pictures can be made in small aperture telescopes.
> 
> 
> 
> Peter
> 
> 
> 
> 
> > From: mbartels at bbastrodesigns.com
> > To: atm at atmlist.net
> > Date: Fri, 1 May 2009 18:02:42 -0700
> > Subject: Re: [ATM] Working with thin mirrors
> > 
> > > Oh and my goals are:
> > >? 
> > > Enough aperture to see faint deep sky objects such as
> > > galaxies but also fast enough and a large viewing field to
> > > see larger objects such as nebulae. 
> > >? 
> > > Is it possible to see color in nebula with a 14" or
> > > 16" telescope? That would be impressive as I have never
> > > seen color in deep sky objects before.
> > 
> > 
> > 
> > >From the optimum detection magnification graphs, it appears that 
> 16 inches
> > of aperture is at the tradeoff point. Diminishing returns set in 
> for larger
> > apertures. Of course, for those objects not visible in a 16 inch 
> scope...
> > http://www.bbastrodesigns.com/dnld/odm.zip 
> > 
> > This could be the basis for so many scopes being 16 inches in 
> aperture.
> > Witness last year's Oregon Star Party Walkabout where the average 
> scope size
> > was a 16 inch. 
> http://www.bbastrodesigns.com/osp08/osp08walkabout.html 
> > 
> > Color is illusive in 40 inch scopes.
> > 
> > Mel Bartels
> 
> > _______________________________________________
> > ATM mailing list http://www.atmlist.net/
> 
> _________________________________________________________________
> Insert movie times and more without leaving Hotmail?.
>
http://windowslive.com/Tutorial/Hotmail/QuickAdd?ocid=TXT_TAGLM_WL_HM_Tut
orial_QuickAdd1_052009
> _______________________________________________
> ATM mailing list http://www.atmlist.net/
> 
> 
> 
>       
> _______________________________________________
> ATM mailing list http://www.atmlist.net/
> 

____________________________________________________________
Click to learn about options trading and get the latest information.
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From stainless_steel at suddenlink.net  Mon May  4 04:08:35 2009
From: stainless_steel at suddenlink.net (stainless_steel at suddenlink.net)
Date: Sun, 3 May 2009 14:08:35 -0500
Subject: [ATM] Working with thin mirrors
In-Reply-To: <001e01c9cac1$b7b681e0$272385a0$@com>
References: <566476.16564.qm@web81905.mail.mud.yahoo.com><542942.93754.qm@web54502.mail.re2.yahoo.com>
	<001e01c9cac1$b7b681e0$272385a0$@com>
Message-ID: <3FE0BC550BA5471092CD379CE7472A72@R101>

Mel,

I remember many, many, many years ago, reading an article in Sky ands Scope 
about some fellows (ooops!- "ATMs") who built two rather largish fork 
equatorially mounted Newts out of exotic lightweight material (they were 
both white in color, and good looking) and were one person transportable- a 
16" and a 20". One looked like a smaller clone of the other. In the 
interesting article, what stood out the most, I mean, what struck me the 
most, was this comment, and I am sure that I remember it word for word (at 
least the important word(s), which I shall capitalize) "... brightness, 
contrast,  and color in the 20", when using the two along side each other, 
was DEFINITELY SUPERIOR to that of the 16 inch..."

For what it's worth...

DLZ-130


----- Original Message ----- 
From: "Mel Bartels" <mbartels at bbastrodesigns.com>
To: <atm at atmlist.net>
Sent: Friday, May 01, 2009 8:02 PM
Subject: Re: [ATM] Working with thin mirrors


> Oh and my goals are:
>
> Enough aperture to see faint deep sky objects such as
> galaxies but also fast enough and a large viewing field to
> see larger objects such as nebulae.
>
> Is it possible to see color in nebula with a 14" or
> 16" telescope? That would be impressive as I have never
> seen color in deep sky objects before.



>From the optimum detection magnification graphs, it appears that 16 inches
of aperture is at the tradeoff point.  Diminishing returns set in for larger
apertures.  Of course, for those objects not visible in a 16 inch scope...
http://www.bbastrodesigns.com/dnld/odm.zip

This could be the basis for so many scopes being 16 inches in aperture.
Witness last year's Oregon Star Party Walkabout where the average scope size
was a 16 inch.  http://www.bbastrodesigns.com/osp08/osp08walkabout.html

Color is illusive in 40 inch scopes.

Mel Bartels


_______________________________________________
ATM mailing list http://www.atmlist.net/


--------------------------------------------------------------------------------



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From tom at moulton.us  Mon May  4 05:58:29 2009
From: tom at moulton.us (Thomas A. Moulton)
Date: Sun, 03 May 2009 16:58:29 -0400
Subject: [ATM] Working with thin mirrors
In-Reply-To: <20090503.112230.3572.0.jkoptic@juno.com>
References: <20090503.112230.3572.0.jkoptic@juno.com>
Message-ID: <49FE0575.8080207@moulton.us>

Let's also not forget that about 30% of men have some form of color 
blindness!

Jarvis Krumbein wrote:
> I think everyone is overlooking the difference in sensitivity of the eye
> between the rods and cones.  much higher light levels are required to
> activate the color sensors.  Diffuse objects, with rare exception, have
> very low average light levels while stellar and planetary objects are
> much more concentrated and therefore have much higher light levels thus
> color can be seen.
>
> Jarvis Krumbein
>
> On Sun, 3 May 2009 06:54:36 -0700 (PDT) Mircea Pteancu
> <mirceapte at yahoo.com> writes:
>   
>> I hope  I will not upset anybody, I'm age 54 but I'm a small guy 
>> compared to you.My telescope is a small Dobsonian of 125mm F/7 but 
>> for me the sky is full of colour.Planetary discs are in strong 
>> dominant colours with subtle hues and tints,this is why since 
>> ancient times they was associated with metals. And the stars have 
>> many different colours,particularly visible at double star or large 
>> rezolved open cluster observations.Deep-Sky objects not so,but in 
>> M42, at least, I saw three colours.Not speaking about the Moon,what 
>> a beauty, or the colours of  bright comets or of the rare 
>> fireballs.Maybe it is something wrong with me or my equipment,the 
>> most complex eyepieces I'm using are Erfles.Regards,Mircea
>>     

From rmay at nethere.com  Mon May  4 07:06:34 2009
From: rmay at nethere.com (Bob May)
Date: Sun, 3 May 2009 15:06:34 -0700
Subject: [ATM] Working with thin mirrors
References: <798952.442.qm@web35803.mail.mud.yahoo.com>
Message-ID: <000901c9cc3b$6ce73bc0$8f78fea9@amd>

Yep, all of the planets are bright enough to excite the color
sensors in the eyes.  Most stars are also able to do this with
only the ones that are barely visible not being seen in color.
For those who have a significant amount of water in the sky, the
stars have a lot more color than they do in the dry areas as the
dry areas tend to make a lot more rresolution than the wet areas.
Thus, in the dry areas, the stars tend to take on a white
appearance with a ring of color where the brightness of the star
isn't so great.
Bob May

rmay at nethere.com
http: slash /nav.to slash bobmay
http: slash /bobmay dot astronomy.net



From toolontop at yahoo.com  Mon May  4 15:27:02 2009
From: toolontop at yahoo.com (Mark Cowan)
Date: Sun, 3 May 2009 23:27:02 -0700 (PDT)
Subject: [ATM] Working with thin mirrors
Message-ID: <813285.3747.qm@web90406.mail.mud.yahoo.com>


Hi Tom,

No, let's do forget that!  Research indicates a far lesser distribution, to wit (from Wikipedia attributed sources):

"There are far more males who are color blind than there are females. Between five and eight percent of males, but less than one percent of females, are color blind."

(Sharpe, LT; Stockman A, J?gle H, Nathans J (1999). "Opsin genes, cone photopigments, color vision and color blindness", in Gegenfurtner KR, Sharpe LT: Color Vision: From Genes to Perception. Cambridge University Press. ISBN 9780521004398.)

I suspect the exaggeration results from a different likely sex-linked difference in brain function, not color blindness but color ignorance...

I have mild red-green color blindness, but that just results in difficulty distinguishing pastel shades of red (and renders gray somewhat greenish). 

Best,
Mark

--- On Sun, 5/3/09, Thomas A. Moulton <tom at moulton.us> wrote:


> Let's also not forget that about 30%
> of men have some form of color blindness!






      

From toolontop at yahoo.com  Mon May  4 15:45:49 2009
From: toolontop at yahoo.com (Mark Cowan)
Date: Sun, 3 May 2009 23:45:49 -0700 (PDT)
Subject: [ATM] Making Thin mirrors
Message-ID: <901300.91575.qm@web90404.mail.mud.yahoo.com>


Tony,

As to the original question - no you wouldn't be crazy.  You might find it tough going though to do something like a 16" f/4 on 3/4" plate if jumping up from a full thickness 9" Pyrex mirror though, due to thermal effects and the 21:1 aspect ratio conspiring against you.  Going fast will call for a large sag as well, 1/4" on a 16" f/4, but that isn't going to make it any more impossible.  A trip through the ATM list archives with the search of "thin mirrors" will yield more than most people can easily digest...

Best,
Mark 

--- On Fri, 5/1/09, TONY BLAKESLEY <blaktony86 at yahoo.com> wrote:

>
> I had to order some new pitch at gotgrit.com because my
> pitch was over 7 years old and used many times (risking
> contamination) so I went and ordered some. I saw they had
> plate glass mirrors at got grit in 3/4" thickness. Would it
> be crazy for me to do a 14 or 16" in this thickness? I would
> prefer about an F/4 to F/5. 
>
 ?
> 


      

From tom at moulton.us  Mon May  4 19:32:04 2009
From: tom at moulton.us (Thomas A. Moulton)
Date: Mon, 04 May 2009 06:32:04 -0400
Subject: [ATM] Making Thin mirrors
In-Reply-To: <901300.91575.qm@web90404.mail.mud.yahoo.com>
References: <901300.91575.qm@web90404.mail.mud.yahoo.com>
Message-ID: <49FEC424.2000209@moulton.us>

At the risk of being biased, I have to jump in and comment.

Any time anyone asks about the 16" I always warn them it is a large 
undertaking.
Heck a 16" Full thickness mirror is no easy task, but 3/4" makes it harder.

The biggest question I ask is: Do you have anyone on hand who has 
experience with thin mirrors?

The ATM archives do have a wealth of information, but nothing beats 
first hand experience on site.

Tom
GotGrit.com

Mark Cowan wrote:
> Tony,
>
> As to the original question - no you wouldn't be crazy.  You might find it tough going though to do something like a 16" f/4 on 3/4" plate if jumping up from a full thickness 9" Pyrex mirror though, due to thermal effects and the 21:1 aspect ratio conspiring against you.  Going fast will call for a large sag as well, 1/4" on a 16" f/4, but that isn't going to make it any more impossible.  A trip through the ATM list archives with the search of "thin mirrors" will yield more than most people can easily digest...
>
> Best,
> Mark 
>
> --- On Fri, 5/1/09, TONY BLAKESLEY <blaktony86 at yahoo.com> wrote:
>
>   
>> I had to order some new pitch at gotgrit.com because my
>> pitch was over 7 years old and used many times (risking
>> contamination) so I went and ordered some. I saw they had
>> plate glass mirrors at got grit in 3/4" thickness. Would it
>> be crazy for me to do a 14 or 16" in this thickness? I would
>> prefer about an F/4 to F/5. 
>>
>>     
>   
>   
>
>
>       
> _______________________________________________
> ATM mailing list http://www.atmlist.net/
>
>
>   

From dlwebb at canit.se  Tue May  5 01:46:32 2009
From: dlwebb at canit.se (Dominic-Luc Webb)
Date: Mon, 4 May 2009 18:46:32 +0200 (MET DST)
Subject: [ATM] Working with thin mirrors
In-Reply-To: <mailman.269.1241212909.7676.atm@atmlist.net>
Message-ID: <Pine.LNX.4.44.0905041829580.22342-100000@uno.canit.se>

On Fri, 1 May 2009, TONY B wrote:

>   ok, great. I guess the bigger the better right?

I will share with you a secret I have kept for many years.
Size doesn't matter! You can beat the church into proving
the Earth is round by little more than poking a stick in
the ground.

Dominic


From dlwebb at canit.se  Tue May  5 01:51:22 2009
From: dlwebb at canit.se (Dominic-Luc Webb)
Date: Mon, 4 May 2009 18:51:22 +0200 (MET DST)
Subject: [ATM] Working with thin mirrors
In-Reply-To: <BLU137-W1001416C8272364838B929B26B0@phx.gbl>
Message-ID: <Pine.LNX.4.44.0905041848530.22342-100000@uno.canit.se>

On Sun, 3 May 2009, Peter De Baan wrote:

>
> I believe that very few people have directly, that is with a telescope,
> seen much colors in the nighttime sky, because of our limited color
> vision capacety at nighttime.

... and because of our limited range of detectable wavelengths.
Much going on in the infrared, for instance, no way to see this
anyway.

Dominic


From jgmoreau at cablevision.qc.ca  Tue May  5 05:07:10 2009
From: jgmoreau at cablevision.qc.ca (Jean Guy Moreau)
Date: Mon, 4 May 2009 16:07:10 -0400
Subject: [ATM] Color perception   was  Working with thin mirrors
In-Reply-To: <813285.3747.qm@web90406.mail.mud.yahoo.com>
References: <813285.3747.qm@web90406.mail.mud.yahoo.com>
Message-ID: <C8DD75DE849F410C9EE4F666667701E3@JeanGuyPC>

Take a test at :

http://www.xrite.com/custom_page.aspx?PageID=77

JG


----- Original Message ----- 
From: "Mark Cowan" <toolontop at yahoo.com>
To: <atm at atmlist.net>
Sent: Monday, May 04, 2009 2:27 AM
Subject: Re: [ATM] Working with thin mirrors



Hi Tom,

No, let's do forget that!  Research indicates a far lesser distribution, to 
wit (from Wikipedia attributed sources):

"There are far more males who are color blind than there are females. 
Between five and eight percent of males, but less than one percent of 
females, are color blind."

(Sharpe, LT; Stockman A, J?gle H, Nathans J (1999). "Opsin genes, cone 
photopigments, color vision and color blindness", in Gegenfurtner KR, Sharpe 
LT: Color Vision: From Genes to Perception. Cambridge University Press. ISBN 
9780521004398.)

I suspect the exaggeration results from a different likely sex-linked 
difference in brain function, not color blindness but color ignorance...

I have mild red-green color blindness, but that just results in difficulty 
distinguishing pastel shades of red (and renders gray somewhat greenish).

Best,
Mark

--- On Sun, 5/3/09, Thomas A. Moulton <tom at moulton.us> wrote:


> Let's also not forget that about 30%
> of men have some form of color blindness!







_______________________________________________
ATM mailing list http://www.atmlist.net/


From djd521 at verizon.net  Tue May  5 05:27:57 2009
From: djd521 at verizon.net (Don D'Egidio)
Date: Mon, 04 May 2009 16:27:57 -0400
Subject: [ATM] Color perception   was  Working with thin mirrors
References: <813285.3747.qm@web90406.mail.mud.yahoo.com>
	<C8DD75DE849F410C9EE4F666667701E3@JeanGuyPC>
Message-ID: <1DEF316C558843488938785A8222C463@donaldp4>

I scored a 32 with these 56 year old eyes.

Don

----- Original Message ----- 
From: "Jean Guy Moreau" <jgmoreau at cablevision.qc.ca>
To: "Mark Cowan" <toolontop at yahoo.com>; <atm at atmlist.net>
Sent: Monday, May 04, 2009 4:07 PM
Subject: Re: [ATM] Color perception was Working with thin mirrors


Take a test at :

http://www.xrite.com/custom_page.aspx?PageID=77

JG






From alaskawolfjoe at hotmail.com  Tue May  5 06:14:29 2009
From: alaskawolfjoe at hotmail.com (lance clarke)
Date: Mon, 4 May 2009 17:14:29 -0400
Subject: [ATM] Color perception   was  Working with thin mirrors
In-Reply-To: <1DEF316C558843488938785A8222C463@donaldp4>
References: <813285.3747.qm@web90406.mail.mud.yahoo.com>
	<C8DD75DE849F410C9EE4F666667701E3@JeanGuyPC> 
	<1DEF316C558843488938785A8222C463@donaldp4>
Message-ID: <COL113-W6036A13C233F5F88DEC739A8680@phx.gbl>


Thanks for the link to the test...very interesting process!  I scored 4 with my 48 year old eyes, but I also have practice.  My wife is a quilter, and she often asks me to judge hues.  She'll get a big kick out of the test.

 

Thanks again.

(and yes, you can see colours with a telescope.  Even my 8" easily shows a green colour to the orion nebula. However, you won't see the spectacular colours of photographs.  But that doesn't detract from visual observing, at least for me.  I still get a kick of thinking to myself "That photon from M31 traveled for 2.5 million years, and now my retina has stopped it!")

 

Lance
 
> From: djd521 at verizon.net
> To: jgmoreau at cablevision.qc.ca; toolontop at yahoo.com; atm at atmlist.net
> Date: Mon, 4 May 2009 16:27:57 -0400
> Subject: Re: [ATM] Color perception was Working with thin mirrors
> 
> I scored a 32 with these 56 year old eyes.
> 
> Don
> 
> ----- Original Message ----- 
> From: "Jean Guy Moreau" <jgmoreau at cablevision.qc.ca>
> To: "Mark Cowan" <toolontop at yahoo.com>; <atm at atmlist.net>
> Sent: Monday, May 04, 2009 4:07 PM
> Subject: Re: [ATM] Color perception was Working with thin mirrors
> 
> 
> Take a test at :
> 
> http://www.xrite.com/custom_page.aspx?PageID=77
> 
> JG
> 
> 
> 
> 
> 
> _______________________________________________
> ATM mailing list http://www.atmlist.net/

_________________________________________________________________
Create a cool, new character for your Windows Live? Messenger. 
http://go.microsoft.com/?linkid=9656621

From richard at foucault.co.uk  Tue May  5 06:15:30 2009
From: richard at foucault.co.uk (Richard in the UK)
Date: Mon, 4 May 2009 22:15:30 +0100
Subject: [ATM] Color perception   was  Working with thin mirrors
In-Reply-To: <1DEF316C558843488938785A8222C463@donaldp4>
References: <813285.3747.qm@web90406.mail.mud.yahoo.com>
	<C8DD75DE849F410C9EE4F666667701E3@JeanGuyPC>
	<1DEF316C558843488938785A8222C463@donaldp4>
Message-ID: <789448399.20090504221530@foucault.co.uk>

Hello Don,

Monday, May 4, 2009, 9:27:57 PM, you wrote:

> http://www.xrite.com/custom_page.aspx?PageID=77

Scored 4 (block of 4, 1 before the end)

-- 
Best regards,
 Richard in the UK


From jhm.vangastel at ziggo.nl  Tue May  5 06:49:55 2009
From: jhm.vangastel at ziggo.nl (Jan van Gastel)
Date: Mon, 4 May 2009 23:49:55 +0200
Subject: [ATM] Color perception   was  Working with thin mirrors
References: <813285.3747.qm@web90406.mail.mud.yahoo.com>
	<C8DD75DE849F410C9EE4F666667701E3@JeanGuyPC>
	<1DEF316C558843488938785A8222C463@donaldp4>
Message-ID: <4908B5875C3C4FC189ECB74DA776407B@niks03981037eb>

I am 61 and scored 19.

Jan
http://members.ziggo.nl/jhm.vangastel/Astronomy/



----- Original Message ----- 
From: "Don D'Egidio" <djd521 at verizon.net>
To: "Jean Guy Moreau" <jgmoreau at cablevision.qc.ca>; "Mark Cowan" 
<toolontop at yahoo.com>; <atm at atmlist.net>
Sent: Monday, May 04, 2009 22:27
Subject: Re: [ATM] Color perception was Working with thin mirrors


>I scored a 32 with these 56 year old eyes.
>
> Don
>
> ----- Original Message ----- 
> From: "Jean Guy Moreau" <jgmoreau at cablevision.qc.ca>
> To: "Mark Cowan" <toolontop at yahoo.com>; <atm at atmlist.net>
> Sent: Monday, May 04, 2009 4:07 PM
> Subject: Re: [ATM] Color perception was Working with thin mirrors
>
>
> Take a test at :
>
> http://www.xrite.com/custom_page.aspx?PageID=77
>
> JG
>
>
>
>
>
> _______________________________________________
> ATM mailing list http://www.atmlist.net/ 


From hermit at outofoptions.org  Tue May  5 06:55:15 2009
From: hermit at outofoptions.org (hermit)
Date: Mon, 04 May 2009 17:55:15 -0400
Subject: [ATM] Color perception   was  Working with thin mirrors
In-Reply-To: <COL113-W6036A13C233F5F88DEC739A8680@phx.gbl>
References: <813285.3747.qm@web90406.mail.mud.yahoo.com>	<C8DD75DE849F410C9EE4F666667701E3@JeanGuyPC>
	<1DEF316C558843488938785A8222C463@donaldp4>
	<COL113-W6036A13C233F5F88DEC739A8680@phx.gbl>
Message-ID: <49FF6443.4020607@outofoptions.org>

Interesting test, but if you don't have a calibrated monitor, it may not 
mean much. I got an LCD about a year ago and it is SOOOOO much nicer 
than the old crt I had. I got a 4 and I'm 57. Messed up the middle 
blocks in the bottom row. I wouldn't have done anywhere as well with the 
old monitor. I know that for fact. In one forum I go to, I thought a guy 
was using a monochrome avatar. When I got the new monitor, I realized he 
wasn't.

Ken Lowther


lance clarke wrote:
> Thanks for the link to the test...very interesting process!  I scored 4 with my 48 year old eyes, but I also have practice.  My wife is a quilter, and she often asks me to judge hues.  She'll get a big kick out of the test.
>
>  
>
> Thanks again.
>
> (and yes, you can see colours with a telescope.  Even my 8" easily shows a green colour to the orion nebula. However, you won't see the spectacular colours of photographs.  But that doesn't detract from visual observing, at least for me.  I still get a kick of thinking to myself "That photon from M31 traveled for 2.5 million years, and now my retina has stopped it!")
>
>  
>
> Lance
>  
>   
>> From: djd521 at verizon.net
>> To: jgmoreau at cablevision.qc.ca; toolontop at yahoo.com; atm at atmlist.net
>> Date: Mon, 4 May 2009 16:27:57 -0400
>> Subject: Re: [ATM] Color perception was Working with thin mirrors
>>
>> I scored a 32 with these 56 year old eyes.
>>
>> Don
>>
>> ----- Original Message ----- 
>> From: "Jean Guy Moreau" <jgmoreau at cablevision.qc.ca>
>> To: "Mark Cowan" <toolontop at yahoo.com>; <atm at atmlist.net>
>> Sent: Monday, May 04, 2009 4:07 PM
>> Subject: Re: [ATM] Color perception was Working with thin mirrors
>>
>>
>> Take a test at :
>>
>> http://www.xrite.com/custom_page.aspx?PageID=77
>>
>> JG
>>
>>
>>
>>
>>
>> _______________________________________________
>> ATM mailing list http://www.atmlist.net/
>>     
>
> _________________________________________________________________
> Create a cool, new character for your Windows Live? Messenger. 
> http://go.microsoft.com/?linkid=9656621
> _______________________________________________
> ATM mailing list http://www.atmlist.net/
>   


From tom at moulton.us  Tue May  5 07:01:03 2009
From: tom at moulton.us (Thomas A. Moulton)
Date: Mon, 04 May 2009 18:01:03 -0400
Subject: [ATM] Color perception   was  Working with thin mirrors
In-Reply-To: <4908B5875C3C4FC189ECB74DA776407B@niks03981037eb>
References: <813285.3747.qm@web90406.mail.mud.yahoo.com>	<C8DD75DE849F410C9EE4F666667701E3@JeanGuyPC>	<1DEF316C558843488938785A8222C463@donaldp4>
	<4908B5875C3C4FC189ECB74DA776407B@niks03981037eb>
Message-ID: <49FF659F.4020704@moulton.us>

Month away from 50 and scored 44

Jan van Gastel wrote:
> I am 61 and scored 19.
>
> Jan
> http://members.ziggo.nl/jhm.vangastel/Astronomy/
>
>
>
> ----- Original Message ----- From: "Don D'Egidio" <djd521 at verizon.net>
> To: "Jean Guy Moreau" <jgmoreau at cablevision.qc.ca>; "Mark Cowan" 
> <toolontop at yahoo.com>; <atm at atmlist.net>
> Sent: Monday, May 04, 2009 22:27
> Subject: Re: [ATM] Color perception was Working with thin mirrors
>
>
>> I scored a 32 with these 56 year old eyes.
>>
>> Don
>>
>> ----- Original Message ----- From: "Jean Guy Moreau" 
>> <jgmoreau at cablevision.qc.ca>
>> To: "Mark Cowan" <toolontop at yahoo.com>; <atm at atmlist.net>
>> Sent: Monday, May 04, 2009 4:07 PM
>> Subject: Re: [ATM] Color perception was Working with thin mirrors
>>
>>
>> Take a test at :
>>
>> http://www.xrite.com/custom_page.aspx?PageID=77
>>
>> JG
>>
>>
>>
>>
>>
>> _______________________________________________
>> ATM mailing list http://www.atmlist.net/ 
>
> _______________________________________________
> ATM mailing list http://www.atmlist.net/
>
>

From baldjeff at comcast.net  Tue May  5 07:42:07 2009
From: baldjeff at comcast.net (Jeff Baldwin)
Date: Mon, 4 May 2009 15:42:07 -0700
Subject: [ATM] Color perception   was  Working with thin mirrors
References: <813285.3747.qm@web90406.mail.mud.yahoo.com>	<C8DD75DE849F410C9EE4F666667701E3@JeanGuyPC><1DEF316C558843488938785A8222C463@donaldp4><COL113-W6036A13C233F5F88DEC739A8680@phx.gbl>
	<49FF6443.4020607@outofoptions.org>
Message-ID: <88225A4D61CB4F4C913DFC300A5A6C66@glendaspc>

I'm 51.22 years old and I scored 15. My monitor is 5 years old. This was a 
cool test. I'm also a pilot, and color blindness is a factor in flying. I'm 
also really curious where I went wrong. I may try this on the wife's lcd 
monitor. I may cheat and let my wife do the test and then tell you guys it 
was me.
Neat test guys,
Bald

Jeff and Glenda Baldwin
Lathrop, CA
www.agetawaylogcabin.com
www.stocktonastro.org

----- Original Message ----- 
From: "hermit" <hermit at outofoptions.org>
Cc: <atm at atmlist.net>
Sent: Monday, May 04, 2009 2:55 PM
Subject: Re: [ATM] Color perception was Working with thin mirrors


Interesting test, but if you don't have a calibrated monitor, it may not
mean much. I got an LCD about a year ago and it is SOOOOO much nicer
than the old crt I had. I got a 4 and I'm 57. Messed up the middle
blocks in the bottom row. I wouldn't have done anywhere as well with the
old monitor. I know that for fact. In one forum I go to, I thought a guy
was using a monochrome avatar. When I got the new monitor, I realized he
wasn't.

Ken Lowther


lance clarke wrote:
> Thanks for the link to the test...very interesting process!  I scored 4 
> with my 48 year old eyes, but I also have practice.  My wife is a quilter, 
> and she often asks me to judge hues.  She'll get a big kick out of the 
> test.
>
>
> Thanks again.
>
> (and yes, you can see colours with a telescope.  Even my 8" easily shows a 
> green colour to the orion nebula. However, you won't see the spectacular 
> colours of photographs.  But that doesn't detract from visual observing, 
> at least for me.  I still get a kick of thinking to myself "That photon 
> from M31 traveled for 2.5 million years, and now my retina has stopped 
> it!")
>
>
> Lance
>
>> From: djd521 at verizon.net
>> To: jgmoreau at cablevision.qc.ca; toolontop at yahoo.com; atm at atmlist.net
>> Date: Mon, 4 May 2009 16:27:57 -0400
>> Subject: Re: [ATM] Color perception was Working with thin mirrors
>>
>> I scored a 32 with these 56 year old eyes.
>>
>> Don
>>
>> ----- Original Message ----- 
>> From: "Jean Guy Moreau" <jgmoreau at cablevision.qc.ca>
>> To: "Mark Cowan" <toolontop at yahoo.com>; <atm at atmlist.net>
>> Sent: Monday, May 04, 2009 4:07 PM
>> Subject: Re: [ATM] Color perception was Working with thin mirrors
>>
>>
>> Take a test at :
>>
>> http://www.xrite.com/custom_page.aspx?PageID=77
>>
>> JG
>>
>>
>>
>>
>>
>> _______________________________________________
>> ATM mailing list http://www.atmlist.net/
>>
>
> _________________________________________________________________
> Create a cool, new character for your Windows Live? Messenger. 
> http://go.microsoft.com/?linkid=9656621
> _______________________________________________
> ATM mailing list http://www.atmlist.net/
>

_______________________________________________
ATM mailing list http://www.atmlist.net/


From al at sgi.com  Tue May  5 08:26:45 2009
From: al at sgi.com (Alexis Cousein)
Date: Tue, 05 May 2009 01:26:45 +0200
Subject: [ATM] Color perception   was  Working with thin mirrors
In-Reply-To: <C8DD75DE849F410C9EE4F666667701E3@JeanGuyPC>
References: <813285.3747.qm@web90406.mail.mud.yahoo.com>
	<C8DD75DE849F410C9EE4F666667701E3@JeanGuyPC>
Message-ID: <49FF79B5.6000302@sgi.com>

Jean Guy Moreau wrote:
> Take a test at :
> 
> http://www.xrite.com/custom_page.aspx?PageID=77
> 
0, at age 41. But I "blame" it on the good LCD monitor as well
as my eyes (though I still miss my Silicon Graphics 1600SW
monitor).

That, and the fact that one of my employer's largest customers
(at 33% of annual sales) used to be the designers of Barco
Creator (the predecessor to the much stripped down Esko Colortone).




From baldjeff at comcast.net  Tue May  5 08:29:12 2009
From: baldjeff at comcast.net (Jeff Baldwin)
Date: Mon, 4 May 2009 16:29:12 -0700
Subject: [ATM] Color perception   was  Working with thin mirrors
References: <813285.3747.qm@web90406.mail.mud.yahoo.com><C8DD75DE849F410C9EE4F666667701E3@JeanGuyPC>
	<49FF79B5.6000302@sgi.com>
Message-ID: <2548FE30BD224037ADA44B1F798EAFD3@glendaspc>

Good job Jean Guy! It's like golf, we want low scores.
JB

Jeff and Glenda Baldwin
Lathrop, CA
www.agetawaylogcabin.com
www.stocktonastro.org

> 0, at age 41. But I "blame" it on the good LCD monitor as well
> as my eyes (though I still miss my Silicon Graphics 1600SW
> monitor).
> 
> That, and the fact that one of my employer's largest customers
> (at 33% of annual sales) used to be the designers of Barco
> Creator (the predecessor to the much stripped down Esko Colortone).


From burrjaw at earthlink.net  Tue May  5 08:58:42 2009
From: burrjaw at earthlink.net (Jim Burrows)
Date: Mon, 04 May 2009 16:58:42 -0700
Subject: [ATM] Color perception   was  Working with thin mirrors
In-Reply-To: <4908B5875C3C4FC189ECB74DA776407B@niks03981037eb>
References: <813285.3747.qm@web90406.mail.mud.yahoo.com>
	<C8DD75DE849F410C9EE4F666667701E3@JeanGuyPC>
	<1DEF316C558843488938785A8222C463@donaldp4>
	<4908B5875C3C4FC189ECB74DA776407B@niks03981037eb>
Message-ID: <E1M186t-00066n-AU@elasmtp-banded.atl.sa.earthlink.net>

At 2009-05-04 23:49 +0200, Jan van Gastel wrote:

>I am 61 and scored 19.

It was a cute test.  At 77, I got same score as age.

         -- Jim Burrows
         -- http://home.earthlink.net/~burrjaw
         -- mailto:burrjaw at earthlink.net
         -- Seattle N47.4723 W122.3662 (WGS84)


From tcohen at blakeglobal.com  Tue May  5 09:27:27 2009
From: tcohen at blakeglobal.com (Ted Cohen)
Date: Mon, 4 May 2009 17:27:27 -0700
Subject: [ATM] Color perception   was  Working with thin mirrors
In-Reply-To: <E1M186t-00066n-AU@elasmtp-banded.atl.sa.earthlink.net>
References: <813285.3747.qm@web90406.mail.mud.yahoo.com><C8DD75DE849F410C9EE4F666667701E3@JeanGuyPC><1DEF316C558843488938785A8222C463@donaldp4><4908B5875C3C4FC189ECB74DA776407B@niks03981037eb>
	<E1M186t-00066n-AU@elasmtp-banded.atl.sa.earthlink.net>
Message-ID: <1CB8B72526694FDCA96932F71EA958EF@BLAKESF.LOCAL>

4 at 43 yrs old



From wa4guu at verizon.net  Tue May  5 09:19:57 2009
From: wa4guu at verizon.net (Jerry)
Date: Mon, 04 May 2009 20:19:57 -0400
Subject: [ATM] Color perception   was  Working with thin mirrors
In-Reply-To: <C8DD75DE849F410C9EE4F666667701E3@JeanGuyPC>
Message-ID: <0D65F30AA78247BC9D48FE36837719B0@D85SJB21>



-----Original Message-----
From: atm-bounces at atmlist.net [mailto:atm-bounces at atmlist.net] On Behalf Of
Jean Guy Moreau
Sent: Monday, May 04, 2009 4:07 PM
To: Mark Cowan; atm at atmlist.net
Subject: Re: [ATM] Color perception was Working with thin mirrors

Take a test at :

http://www.xrite.com/custom_page.aspx?PageID=77

JG


I can't wait to see how Bob May does with the monochrome display.

:-)  Just kidding Bob...



My score was the same as my IQ.

Jerry


From starxplror at comcast.net  Tue May  5 10:50:47 2009
From: starxplror at comcast.net (starxplror at comcast.net)
Date: Tue, 5 May 2009 01:50:47 +0000 (UTC)
Subject: [ATM] Color perception   was  Working with thin mirrors
In-Reply-To: <0D65F30AA78247BC9D48FE36837719B0@D85SJB21>
Message-ID: <2174153.2072121241488247758.JavaMail.root@sz0012a.emeryville.ca.mail.comcast.net>



Way cool!! Scored 11. 



Fred 


----- Original Message ----- 
From: "Jerry" <wa4guu at verizon.net> 
To: atm at atmlist.net 
Sent: Monday, May 4, 2009 5:19:57 PM GMT -08:00 US/Canada Pacific 
Subject: Re: [ATM] Color perception ? was ?Working with thin mirrors 



-----Original Message----- 
From: atm-bounces at atmlist.net [mailto:atm-bounces at atmlist.net] On Behalf Of 
Jean Guy Moreau 
Sent: Monday, May 04, 2009 4:07 PM 
To: Mark Cowan; atm at atmlist.net 
Subject: Re: [ATM] Color perception was Working with thin mirrors 

Take a test at : 

http://www.xrite.com/custom_page.aspx?PageID=77 

JG 


I can't wait to see how Bob May does with the monochrome display. 

:-) ?Just kidding Bob... 



My score was the same as my IQ. 

Jerry 

_______________________________________________ 
ATM mailing list http://www.atmlist.net/ 

From starxplror at comcast.net  Tue May  5 10:56:11 2009
From: starxplror at comcast.net (starxplror at comcast.net)
Date: Tue, 5 May 2009 01:56:11 +0000 (UTC)
Subject: [ATM] Color perception   was  Working with thin mirrors
In-Reply-To: <2174153.2072121241488247758.JavaMail.root@sz0012a.emeryville.ca.mail.comcast.net>
Message-ID: <833519021.2073531241488571073.JavaMail.root@sz0012a.emeryville.ca.mail.comcast.net>



oops, forgot (senior moment). I'm 54 



Fred 


----- Original Message ----- 
From: starxplror at comcast.net 
To: atm at atmlist.net 
Sent: Monday, May 4, 2009 6:50:47 PM GMT -08:00 US/Canada Pacific 
Subject: Re: [ATM] Color perception ? was ?Working with thin mirrors 



Way cool!! Scored 11. 



Fred 


----- Original Message ----- 
From: "Jerry" <wa4guu at verizon.net> 
To: atm at atmlist.net 
Sent: Monday, May 4, 2009 5:19:57 PM GMT -08:00 US/Canada Pacific 
Subject: Re: [ATM] Color perception ? was ?Working with thin mirrors 



-----Original Message----- 
From: atm-bounces at atmlist.net [mailto:atm-bounces at atmlist.net] On Behalf Of 
Jean Guy Moreau 
Sent: Monday, May 04, 2009 4:07 PM 
To: Mark Cowan; atm at atmlist.net 
Subject: Re: [ATM] Color perception was Working with thin mirrors 

Take a test at : 

http://www.xrite.com/custom_page.aspx?PageID=77 

JG 


I can't wait to see how Bob May does with the monochrome display. 

:-) ?Just kidding Bob... 



My score was the same as my IQ. 

Jerry 

_______________________________________________ 
ATM mailing list http://www.atmlist.net/ 
_______________________________________________ 
ATM mailing list http://www.atmlist.net/

From jbentz at inreach.com  Tue May  5 11:18:28 2009
From: jbentz at inreach.com (Jan Bentz)
Date: Mon, 04 May 2009 19:18:28 -0700
Subject: [ATM] Color perception   was  Working with thin mirrors
In-Reply-To: <C8DD75DE849F410C9EE4F666667701E3@JeanGuyPC>
References: <813285.3747.qm@web90406.mail.mud.yahoo.com>
	<C8DD75DE849F410C9EE4F666667701E3@JeanGuyPC>
Message-ID: <49FFA1F4.3030100@inreach.com>

7 @ 65  w/CRT  -- Jan Bentz

From pdebaan at hotmail.com  Tue May  5 11:34:20 2009
From: pdebaan at hotmail.com (Peter De Baan)
Date: Tue, 5 May 2009 02:34:20 +0000
Subject: [ATM] Color perception   was  Working with thin mirrors
In-Reply-To: <49FFA1F4.3030100@inreach.com>
References: <813285.3747.qm@web90406.mail.mud.yahoo.com>
	<C8DD75DE849F410C9EE4F666667701E3@JeanGuyPC>
	<49FFA1F4.3030100@inreach.com>
Message-ID: <BLU137-W5D88EC4294AE84C12D989B2690@phx.gbl>



 Well I knew I could beet you all and being color blind helped me (as always)  Age 77 score 125

 (You know the alleid bombers during WWII used color blind people to see the "camouflaged" German bunkers etc. for they stood out like sore thumb, and since most people are color blind to the red side most see very good close to the UV and have better night vision.)

Thank you all 

Peter 

 
> Date: Mon, 4 May 2009 19:18:28 -0700
> From: jbentz at inreach.com
> To: jgmoreau at cablevision.qc.ca
> CC: atm at atmlist.net
> Subject: Re: [ATM] Color perception was Working with thin mirrors
> 
> 7 @ 65 w/CRT -- Jan Bentz
> _______________________________________________
> ATM mailing list http://www.atmlist.net/

_________________________________________________________________
Windows Live?: Keep your life in sync.
http://windowslive.com/explore?ocid=TXT_TAGLM_BR_life_in_synch_052009

From jkoptic at juno.com  Tue May  5 11:36:06 2009
From: jkoptic at juno.com (Jarvis Krumbein)
Date: Mon, 4 May 2009 19:36:06 -0700
Subject: [ATM] Color perception   was  Working with thin mirrors
Message-ID: <20090504.193606.1308.0.jkoptic@juno.com>

The test for color perception is very interesting.  I got a score of 20
which is pretty good for 78 year old eyes.  A good LCD screen helps.  I
used to give color perception tests when I was running electronic
equipment production many years ago.  I was always amazed when none of
the women on the production line had any trace of color blindness but a
very large percentage (over 30%) of the men had some degree ranging from
almost complete color blindness to very slight where only subtle
variations posed a problem.  Since color coding was all important,
careful job assignment was critical and the worst cases always did the
mechanical assembly work.  My father-in-law was associated with on of the
larger paint companies and told me that their best color matchers were
all very color blind.  They were no good for major color differences but
for matching subtle shade variations of the same color, they couldn't be
beat.

Jarvis Krumbein

On Mon, 4 May 2009 16:07:10 -0400 "Jean Guy Moreau"
<jgmoreau at cablevision.qc.ca> writes:
> Take a test at :
> 
> http://www.xrite.com/custom_page.aspx?PageID=77
> 
> JG
> 
> 
> ----- Original Message ----- 
> From: "Mark Cowan" <toolontop at yahoo.com>
> To: <atm at atmlist.net>
> Sent: Monday, May 04, 2009 2:27 AM
> Subject: Re: [ATM] Working with thin mirrors
> 
> 
> 
> Hi Tom,
> 
> No, let's do forget that!  Research indicates a far lesser 
> distribution, to 
> wit (from Wikipedia attributed sources):
> 
> "There are far more males who are color blind than there are 
> females. 
> Between five and eight percent of males, but less than one percent 
> of 
> females, are color blind."
> 
> (Sharpe, LT; Stockman A, J?gle H, Nathans J (1999). "Opsin genes, 
> cone 
> photopigments, color vision and color blindness", in Gegenfurtner 
> KR, Sharpe 
> LT: Color Vision: From Genes to Perception. Cambridge University 
> Press. ISBN 
> 9780521004398.)
> 
> I suspect the exaggeration results from a different likely 
> sex-linked 
> difference in brain function, not color blindness but color 
> ignorance...
> 
> I have mild red-green color blindness, but that just results in 
> difficulty 
> distinguishing pastel shades of red (and renders gray somewhat 
> greenish).
> 
> Best,
> Mark
> 
> --- On Sun, 5/3/09, Thomas A. Moulton <tom at moulton.us> wrote:
> 
> 
> > Let's also not forget that about 30%
> > of men have some form of color blindness!
> 
> 
> 
> 
> 
> 
> 
> _______________________________________________
> ATM mailing list http://www.atmlist.net/
> 
> _______________________________________________
> ATM mailing list http://www.atmlist.net/
> 

____________________________________________________________
Click here to find a massage therapy school near you. 
http://thirdpartyoffers.juno.com/TGL2141/fc/BLSrjpTEbe2fUGrXNMXVSASOJ0lMCSc2JeHLPI6uBL7kSLD3i8sFyU3w6PG/

From baldjeff at comcast.net  Tue May  5 11:48:37 2009
From: baldjeff at comcast.net (Jeff Baldwin)
Date: Mon, 4 May 2009 19:48:37 -0700
Subject: [ATM] Color perception   was  Working with thin mirrors
References: <20090504.193606.1308.0.jkoptic@juno.com>
Message-ID: <6F9C4D766A834B0D910D943CC0F9D538@glendaspc>

I just took the test again on my wife's LCD and moved from a 15 to an 8. 
Awesome. She got a 29. I would have thought that a female would have gotten 
better color vision than a male, but I guess we all have differences. I'm 
51, she's 54.
Bald

Jeff and Glenda Baldwin
Lathrop, CA
www.agetawaylogcabin.com
www.stocktonastro.org

----- Original Message ----- 
From: "Jarvis Krumbein" <jkoptic at juno.com>
To: <jgmoreau at cablevision.qc.ca>
Cc: <atm at atmlist.net>
Sent: Monday, May 04, 2009 7:36 PM
Subject: Re: [ATM] Color perception was Working with thin mirrors


> The test for color perception is very interesting.  I got a score of 20
> which is pretty good for 78 year old eyes.  A good LCD screen helps.  I
> used to give color perception tests when I was running electronic
> equipment production many years ago.  I was always amazed when none of
> the women on the production line had any trace of color blindness but a
> very large percentage (over 30%) of the men had some degree ranging from
> almost complete color blindness to very slight where only subtle
> variations posed a problem.  Since color coding was all important,
> careful job assignment was critical and the worst cases always did the
> mechanical assembly work.  My father-in-law was associated with on of the
> larger paint companies and told me that their best color matchers were
> all very color blind.  They were no good for major color differences but
> for matching subtle shade variations of the same color, they couldn't be
> beat.
>
> Jarvis Krumbein
>
> On Mon, 4 May 2009 16:07:10 -0400 "Jean Guy Moreau"
> <jgmoreau at cablevision.qc.ca> writes:
>> Take a test at :
>>
>> http://www.xrite.com/custom_page.aspx?PageID=77
>>
>> JG
>>
>>
>> ----- Original Message ----- 
>> From: "Mark Cowan" <toolontop at yahoo.com>
>> To: <atm at atmlist.net>
>> Sent: Monday, May 04, 2009 2:27 AM
>> Subject: Re: [ATM] Working with thin mirrors
>>
>>
>>
>> Hi Tom,
>>
>> No, let's do forget that!  Research indicates a far lesser
>> distribution, to
>> wit (from Wikipedia attributed sources):
>>
>> "There are far more males who are color blind than there are
>> females.
>> Between five and eight percent of males, but less than one percent
>> of
>> females, are color blind."
>>
>> (Sharpe, LT; Stockman A, J?gle H, Nathans J (1999). "Opsin genes,
>> cone
>> photopigments, color vision and color blindness", in Gegenfurtner
>> KR, Sharpe
>> LT: Color Vision: From Genes to Perception. Cambridge University
>> Press. ISBN
>> 9780521004398.)
>>
>> I suspect the exaggeration results from a different likely
>> sex-linked
>> difference in brain function, not color blindness but color
>> ignorance...
>>
>> I have mild red-green color blindness, but that just results in
>> difficulty
>> distinguishing pastel shades of red (and renders gray somewhat
>> greenish).
>>
>> Best,
>> Mark
>>
>> --- On Sun, 5/3/09, Thomas A. Moulton <tom at moulton.us> wrote:
>>
>>
>> > Let's also not forget that about 30%
>> > of men have some form of color blindness!
>>
>>
>>
>>
>>
>>
>>
>> _______________________________________________
>> ATM mailing list http://www.atmlist.net/
>>
>> _______________________________________________
>> ATM mailing list http://www.atmlist.net/
>>
>
> ____________________________________________________________
> Click here to find a massage therapy school near you.
> http://thirdpartyoffers.juno.com/TGL2141/fc/BLSrjpTEbe2fUGrXNMXVSASOJ0lMCSc2JeHLPI6uBL7kSLD3i8sFyU3w6PG/
>


--------------------------------------------------------------------------------


> _______________________________________________
> ATM mailing list http://www.atmlist.net/ 


From lopez at mv.mv.com  Tue May  5 11:49:08 2009
From: lopez at mv.mv.com (Lawrence D. Lopez)
Date: Mon, 04 May 2009 22:49:08 -0400
Subject: [ATM] Color perception   was  Working with thin mirrors
In-Reply-To: <20090504.193606.1308.0.jkoptic@juno.com>
References: <20090504.193606.1308.0.jkoptic@juno.com>
Message-ID: <49FFA924.8020000@mv.mv.com>

I got 22, I'm almost 60, sometimes more, sometimes left.

Jarvis Krumbein wrote:
> The test for color perception is very interesting.  I got a score of 20
> which is pretty good for 78 year old eyes.  A good LCD screen helps.  I
> used to give color perception tests when I was running electronic
> equipment production many years ago.  I was always amazed when none of
> the women on the production line had any trace of color blindness but a
> very large percentage (over 30%) of the men had some degree ranging from
> almost complete color blindness to very slight where only subtle
> variations posed a problem.  Since color coding was all important,
> careful job assignment was critical and the worst cases always did the
> mechanical assembly work.  My father-in-law was associated with on of the
> larger paint companies and told me that their best color matchers were
> all very color blind.  They were no good for major color differences but
> for matching subtle shade variations of the same color, they couldn't be
> beat.
>
> Jarvis Krumbein
>
> On Mon, 4 May 2009 16:07:10 -0400 "Jean Guy Moreau"
> <jgmoreau at cablevision.qc.ca> writes:
>   
>> Take a test at :
>>
>> http://www.xrite.com/custom_page.aspx?PageID=77
>>
>> JG
>>
>>
>> ----- Original Message ----- 
>> From: "Mark Cowan" <toolontop at yahoo.com>
>> To: <atm at atmlist.net>
>> Sent: Monday, May 04, 2009 2:27 AM
>> Subject: Re: [ATM] Working with thin mirrors
>>
>>
>>
>> Hi Tom,
>>
>> No, let's do forget that!  Research indicates a far lesser 
>> distribution, to 
>> wit (from Wikipedia attributed sources):
>>
>> "There are far more males who are color blind than there are 
>> females. 
>> Between five and eight percent of males, but less than one percent 
>> of 
>> females, are color blind."
>>
>> (Sharpe, LT; Stockman A, J?gle H, Nathans J (1999). "Opsin genes, 
>> cone 
>> photopigments, color vision and color blindness", in Gegenfurtner 
>> KR, Sharpe 
>> LT: Color Vision: From Genes to Perception. Cambridge University 
>> Press. ISBN 
>> 9780521004398.)
>>
>> I suspect the exaggeration results from a different likely 
>> sex-linked 
>> difference in brain function, not color blindness but color 
>> ignorance...
>>
>> I have mild red-green color blindness, but that just results in 
>> difficulty 
>> distinguishing pastel shades of red (and renders gray somewhat 
>> greenish).
>>
>> Best,
>> Mark
>>
>> --- On Sun, 5/3/09, Thomas A. Moulton <tom at moulton.us> wrote:
>>
>>
>>     
>>> Let's also not forget that about 30%
>>> of men have some form of color blindness!
>>>       
>>
>>
>>
>>
>>
>> _______________________________________________
>> ATM mailing list http://www.atmlist.net/
>>
>> _______________________________________________
>> ATM mailing list http://www.atmlist.net/
>>
>>     
>
> ____________________________________________________________
> Click here to find a massage therapy school near you. 
> http://thirdpartyoffers.juno.com/TGL2141/fc/BLSrjpTEbe2fUGrXNMXVSASOJ0lMCSc2JeHLPI6uBL7kSLD3i8sFyU3w6PG/
>   
> ------------------------------------------------------------------------
>
> _______________________________________________
> ATM mailing list http://www.atmlist.net/


From atmpob at yahoo.com  Tue May  5 11:51:36 2009
From: atmpob at yahoo.com (Dale Eason)
Date: Mon, 4 May 2009 19:51:36 -0700 (PDT)
Subject: [ATM] Color perception   was  Working with thin mirrors
In-Reply-To: <BLU137-W5D88EC4294AE84C12D989B2690@phx.gbl>
Message-ID: <853385.14774.qm@web54503.mail.re2.yahoo.com>


4 at age 63
Dale Eason


      

From blaktony86 at yahoo.com  Tue May  5 12:27:58 2009
From: blaktony86 at yahoo.com (TONY BLAKESLEY)
Date: Mon, 4 May 2009 20:27:58 -0700 (PDT)
Subject: [ATM] Color perception   was  Working with thin mirrors
In-Reply-To: <853385.14774.qm@web54503.mail.re2.yahoo.com>
Message-ID: <844019.19585.qm@web81903.mail.mud.yahoo.com>

6 at age 23.
Tony Blakesley

--- On Mon, 5/4/09, Dale Eason <atmpob at yahoo.com> wrote:

From: Dale Eason <atmpob at yahoo.com>
Subject: Re: [ATM] Color perception was Working with thin mirrors
To: atm at atmlist.net
Date: Monday, May 4, 2009, 9:51 PM

4 at age 63
Dale Eason


      
_______________________________________________
ATM mailing list http://www.atmlist.net/

From blaktony86 at yahoo.com  Tue May  5 12:43:45 2009
From: blaktony86 at yahoo.com (TONY BLAKESLEY)
Date: Mon, 4 May 2009 20:43:45 -0700 (PDT)
Subject: [ATM] Okie-Tex 2009 and Grinding a 14-16"
Message-ID: <907997.65251.qm@web81906.mail.mud.yahoo.com>

I was wandering if anyone is going to the Okie-Tex star party this year. I have never gone before, but my father and I are planning a trip this September. 
?
I will have my 235mm mirror and scope finished soon and I would like to make my dad a mirror before the star party. He wants a 14-16" mirror. Do you think its feasable to make a 14-16" thin mirror (3/4") within 3-4 months? I have a grinding machine if that helps. My dad will build the scope, as he is a great wood worker. 
?
Too ambitious or feasible? 
?
Here are pics of my nearly finished scope.
?
http://i617.photobucket.com/albums/tt259/coinboy1/CIMG2410.jpg
?
http://i617.photobucket.com/albums/tt259/coinboy1/CIMG2408.jpg
?
-Tony Blakesley

From mbartels at bbastrodesigns.com  Tue May  5 12:48:48 2009
From: mbartels at bbastrodesigns.com (Mel Bartels)
Date: Mon, 4 May 2009 20:48:48 -0700
Subject: [ATM] Color perception   was  Working with thin mirrors
In-Reply-To: <844019.19585.qm@web81903.mail.mud.yahoo.com>
References: <853385.14774.qm@web54503.mail.re2.yahoo.com>
	<844019.19585.qm@web81903.mail.mud.yahoo.com>
Message-ID: <008701c9cd34$78b06770$6a113650$@com>

I got 8 (age 55).  Then I went and played with the gamma setting on my
monitor and found that I could score perfectly.  

Mel Bartels


From mbartels at bbastrodesigns.com  Tue May  5 12:56:01 2009
From: mbartels at bbastrodesigns.com (Mel Bartels)
Date: Mon, 4 May 2009 20:56:01 -0700
Subject: [ATM] Okie-Tex 2009 and Grinding a 14-16"
In-Reply-To: <907997.65251.qm@web81906.mail.mud.yahoo.com>
References: <907997.65251.qm@web81906.mail.mud.yahoo.com>
Message-ID: <008d01c9cd35$6bff3d20$43fdb760$@com>

>>> Do you think its feasable to make a 14-16" thin mirror (3/4") within 3-4
months? I have a grinding machine if that helps. My dad will build the
scope, as he is a great wood worker. 


That's quite an ambitious schedule, even for an experienced large thin
mirror maker.  Aluminizing alone can take a couple of months worse case.

So here's what you can do: set up a project plan with milestones (mirror
acquired by x, rough grinding by x+, fine grinding by x++, etc). Then you'll
know sooner than later if you are going to miss the date.  I suggest one
week to rough grind, one week to fine grind, one week to polish, and 2
months to figure.  That's 3 months right there... 

Have a plan B ready to go...

Mel Bartels



From blaktony86 at yahoo.com  Tue May  5 13:02:11 2009
From: blaktony86 at yahoo.com (TONY B)
Date: Mon, 04 May 2009 23:02:11 CDT
Subject: [ATM] Okie-Tex 2009 and Grinding a 14-16"
Message-ID: <mailman.444.1241496134.7676.atm@atmlist.net>

 yeah i figure it will be cutting it close. Thanks for the tip.  
-----Original Message-----
Date: Monday, May 04, 2009 10:57:17 pm
To: <atm at atmlist.net>
From: "Mel Bartels" <mbartels at bbastrodesigns.com>
Subject: Re: [ATM] Okie-Tex 2009 and Grinding a 14-16"

>>> Do you think its feasable to make a 14-16" thin mirror (3/4") within 3-4
months? I have a grinding machine if that helps. My dad will build the
scope, as he is a great wood worker. 


That's quite an ambitious schedule, even for an experienced large thin
mirror maker.  Aluminizing alone can take a couple of months worse case.

So here's what you can do: set up a project plan with milestones (mirror
acquired by x, rough grinding by x+, fine grinding by x++, etc). Then you'll
know sooner than later if you are going to miss the date.  I suggest one
week to rough grind, one week to fine grind, one week to polish, and 2
months to figure.  That's 3 months right there... 

Have a plan B ready to go...

Mel Bartels


_______________________________________________
ATM mailing list http://www.atmlist.net/



From tillerman1 at videotron.ca  Tue May  5 13:05:44 2009
From: tillerman1 at videotron.ca (George Anderson)
Date: Tue, 05 May 2009 00:05:44 -0400
Subject: [ATM] Color perception   was  Working with thin mirrors
In-Reply-To: <C8DD75DE849F410C9EE4F666667701E3@JeanGuyPC>
References: <813285.3747.qm@web90406.mail.mud.yahoo.com>
	<C8DD75DE849F410C9EE4F666667701E3@JeanGuyPC>
Message-ID: <49FFBB18.2040203@videotron.ca>

Scored a 15 with 51 year old eyes and a ~14 year old monitor. I may try 
again with an LCD at work tomorrow.

George Anderson
Montreal Canada

Clear skies and good health


Jean Guy Moreau wrote:
> Take a test at :
>
> http://www.xrite.com/custom_page.aspx?PageID=77
>
> JG
>
>
> ----- Original Message ----- From: "Mark Cowan" <toolontop at yahoo.com>
> To: <atm at atmlist.net>
> Sent: Monday, May 04, 2009 2:27 AM
> Subject: Re: [ATM] Working with thin mirrors
>
>
>
> Hi Tom,
>
> No, let's do forget that!  Research indicates a far lesser 
> distribution, to wit (from Wikipedia attributed sources):
>
> "There are far more males who are color blind than there are females. 
> Between five and eight percent of males, but less than one percent of 
> females, are color blind."
>
> (Sharpe, LT; Stockman A, J?gle H, Nathans J (1999). "Opsin genes, cone 
> photopigments, color vision and color blindness", in Gegenfurtner KR, 
> Sharpe LT: Color Vision: From Genes to Perception. Cambridge 
> University Press. ISBN 9780521004398.)
>
> I suspect the exaggeration results from a different likely sex-linked 
> difference in brain function, not color blindness but color ignorance...
>
> I have mild red-green color blindness, but that just results in 
> difficulty distinguishing pastel shades of red (and renders gray 
> somewhat greenish).
>
> Best,
> Mark
>
> --- On Sun, 5/3/09, Thomas A. Moulton <tom at moulton.us> wrote:
>
>
>> Let's also not forget that about 30%
>> of men have some form of color blindness!
>
>
>
>
>
>
>
> _______________________________________________
> ATM mailing list http://www.atmlist.net/
>
> _______________________________________________
> ATM mailing list http://www.atmlist.net/
>
>



From atmpob at yahoo.com  Tue May  5 14:03:27 2009
From: atmpob at yahoo.com (Dale Eason)
Date: Mon, 4 May 2009 22:03:27 -0700 (PDT)
Subject: [ATM] Okie-Tex 2009 and Grinding a 14-16"
In-Reply-To: <mailman.444.1241496134.7676.atm@atmlist.net>
Message-ID: <548327.30531.qm@web54507.mail.re2.yahoo.com>


I was there last year with my 16 x 1 inch mirror and scope that I made.  I had the best observing fun ever.  I am planning to go again this year but will have to wait to see how things go.

I agree with Mel about the time frame.  It took me about 6 months to get my mirror done to where I was ready to look through it.  Made the scope about the same time but it was probably a year to first light.  Then another year of "planning" and refiguring to make it even better.

I think it would be close just doing an 8 to 10 inch in the time required but that is me and my schedule.

http://www.okie-tex.com/photos/2008/Eason_DSCN0240.JPG

The spindly scope in the background is my 16 without it's upper light shield.  The man in the forground is not me but a friend and part of our deligation from Minnesota. His telekit scope is right behind him. If you go back up the link by one you can see pictures I and others took last year.


Dale Eason


      

From gfbrandenburg at yahoo.com  Tue May  5 15:15:19 2009
From: gfbrandenburg at yahoo.com (Guy Brandenburg)
Date: Mon, 4 May 2009 23:15:19 -0700 (PDT)
Subject: [ATM] Color perception   was  Working with thin mirrors
Message-ID: <893348.71670.qm@web111503.mail.gq1.yahoo.com>


Neat test! I got 19 at age 59.


      

From djd521 at verizon.net  Tue May  5 16:02:09 2009
From: djd521 at verizon.net (Don D'Egidio)
Date: Tue, 05 May 2009 03:02:09 -0400
Subject: [ATM] Color perception   was  Working with thin mirrors
References: <893348.71670.qm@web111503.mail.gq1.yahoo.com>
Message-ID: <79F322BF70A742F589E57A0EA021776E@donaldp4>

It's been three years since I last used my Spider on the LCD monitor, and now that's it's been 
recalibrated, I scored a 3 on a retest.

Don 




From dlwebb at canit.se  Tue May  5 17:25:27 2009
From: dlwebb at canit.se (Dominic-Luc Webb)
Date: Tue, 5 May 2009 10:25:27 +0200 (MET DST)
Subject: [ATM] Single payer
In-Reply-To: <ba186d1f0905041627r656c8bc2xe0011c6cab35412f@mail.gmail.com>
Message-ID: <Pine.LNX.4.44.0905051023590.8846-100000@uno.canit.se>

On Mon, 4 May 2009, franklin dunn wrote:

> Dominic
>
> All your observations understood. I am hoping my departure for the
> mountains date of May 27 will give enough time for most of these
> possibilities to resolve into firm events one way or the other.
>
> Kim

I suspect the public and government reaction is starting
to wind down. I may try to book a ticket, maybe even today
to head out from Stockholm May 18. In this case, I would
be around on the 27th.

Dominic


From dlwebb at canit.se  Tue May  5 17:29:28 2009
From: dlwebb at canit.se (Dominic-Luc Webb)
Date: Tue, 5 May 2009 10:29:28 +0200 (MET DST)
Subject: [ATM] Single payer
In-Reply-To: <Pine.LNX.4.44.0905051023590.8846-100000@uno.canit.se>
Message-ID: <Pine.LNX.4.44.0905051026510.8846-100000@uno.canit.se>


Please my ignore last email. I accidentally clicked
this list's address in my addressbook instead of
the one next to it that was intended. Sorry.

Dominic


From foreilly at verizon.net  Tue May  5 21:47:28 2009
From: foreilly at verizon.net (Francis J. O'Reilly)
Date: Tue, 05 May 2009 08:47:28 -0400
Subject: [ATM]  Color perception   was  Working with thin mirrors
References: <844019.19585.qm@web81903.mail.mud.yahoo.com>
Message-ID: <B3DA071A86E74578B65EE20E47995C2A@HELENYLCMWAV95>

I scored 13 at 51 years old (January 30, 1958)

I've been in rather bad health lately and on numerous meds. I'll try again 
if I recover after I've been off the meds for a few months.

Francis J. O'Reilly 



From broward32666 at yahoo.com  Tue May  5 22:39:27 2009
From: broward32666 at yahoo.com (Charles Broward)
Date: Tue, 5 May 2009 06:39:27 -0700 (PDT)
Subject: [ATM] Color perception   was  Working with thin mirrors
In-Reply-To: <49FFBB18.2040203@videotron.ca>
References: <813285.3747.qm@web90406.mail.mud.yahoo.com>
	<C8DD75DE849F410C9EE4F666667701E3@JeanGuyPC>
	<49FFBB18.2040203@videotron.ca>
Message-ID: <379239.98555.qm@web110813.mail.gq1.yahoo.com>

At the WSP I never could see carbon stars....now I know why.  I scored 77, with a very good monitor, and
68 year old eyes.  Oh well.

I will still keep looking up.

Chuck in N. florida

 C.S.Broward
GhastlySky Observatory
Gainesville, Florida


WWW.Floridastars.org
ATM Coord, Alcor




________________________________
From: George Anderson <tillerman1 at videotron.ca>
To: ATM List <atm at atmlist.net>
Sent: Tuesday, May 5, 2009 12:05:44 AM
Subject: Re: [ATM] Color perception   was  Working with thin mirrors

Scored a 15 with 51 year old eyes and a ~14 year old monitor. I may try again with an LCD at work tomorrow.

George Anderson
Montreal Canada


      

From dlwebb at canit.se  Tue May  5 23:05:36 2009
From: dlwebb at canit.se (Dominic-Luc Webb)
Date: Tue, 5 May 2009 16:05:36 +0200 (MET DST)
Subject: [ATM] Color perception   was  Working with thin mirrors
In-Reply-To: <379239.98555.qm@web110813.mail.gq1.yahoo.com>
Message-ID: <Pine.LNX.4.44.0905051552110.8431-100000@uno.canit.se>


I think it should be clear this has a learning curve. Work
this exercise every day and you will quickly improve. A
similar thing happens on the first efforts to estimate
magnitudes, and that quickly improves. Inspect that chart
afterwards and you will recognize differences between
adjacent colors that need to be re-arranged. The entire
gradient becomes familiar as your brain sorts out adjacent
squares one at a time. From the start, it may not be clear
visually what constitutes correct ordering, but as you are
provided cues about correct answer, you re-sort. I think
this really means that most of us have good perception, but
the rules and amount of scrutiny needed for correct
ordering must first be learned.

It seems to me that the true measure for any individual
would be the mean score after overcoming the learning
curve. After many attempts, there should be some baseline
error level that cannot be overcome, which presumably
is "physiological"  perception error.

Dominic


From camkit at mweb.co.za  Tue May  5 23:14:51 2009
From: camkit at mweb.co.za (chris forder)
Date: Tue, 05 May 2009 16:14:51 +0200
Subject: [ATM] Color perception
Message-ID: <4A0049DB.7060305@mweb.co.za>

Intersting test,I got 12 with 68 year old eyes. I am also consulted on 
color by my quilter wife.

Chris
Cape town

From lugt at xs4all.nl  Tue May  5 23:28:46 2009
From: lugt at xs4all.nl (Marinus van der Lugt)
Date: Tue, 5 May 2009 16:28:46 +0200
Subject: [ATM] Color perception   was  Working with thin mirrors
In-Reply-To: <008701c9cd34$78b06770$6a113650$@com>
References: <853385.14774.qm@web54503.mail.re2.yahoo.com>
	<844019.19585.qm@web81903.mail.mud.yahoo.com>
	<008701c9cd34$78b06770$6a113650$@com>
Message-ID: <CF182159-5BAF-4A45-A379-C290802068F7@xs4all.nl>

Score 0, age 49, on an Apple Cinema LCD, brightness turned all the way  
up.

Unfortunately I have to buy myself a pair of reading glasses real soon  
now :-(

From astroguy at nas.com  Wed May  6 01:12:13 2009
From: astroguy at nas.com (astroguy at nas.com)
Date: Tue, 5 May 2009 12:12:13 -0400
Subject: [ATM] Color perception - 422
Message-ID: <380-22009525161213155@M2W021.mail2web.com>


Score = 422

I win!!!!

age = 60

I lose...................but I can still rollerblade    :-)






--------------------------------------------------------------------
mail2web.com ? What can On Demand Business Solutions do for you?
http://link.mail2web.com/Business/SharePoint



From broward32666 at yahoo.com  Wed May  6 02:37:11 2009
From: broward32666 at yahoo.com (Charles Broward)
Date: Tue, 5 May 2009 10:37:11 -0700 (PDT)
Subject: [ATM] Color perception   was  Working with thin mirrors
In-Reply-To: <Pine.LNX.4.44.0905051552110.8431-100000@uno.canit.se>
References: <Pine.LNX.4.44.0905051552110.8431-100000@uno.canit.se>
Message-ID: <708469.48327.qm@web110811.mail.gq1.yahoo.com>

Dominic,  I think you are right,  and I will make myself a study of one...

I have been highly impressed with how much I have learned to see over the past few years, and

how much the eye(s)-brain combination works to make a good image from two bad ones!  For intense lunar

viewing I like binoviewers...two eyes seem much better than one.  It will be intriguing to see what happens with

the color thing...

Chuck in N. Fl

 


I think it should be clear this has a learning curve. Work
this exercise every day and you will quickly improve.....
I....t the true measure for any individual
would be the mean score after overcoming the learning
curve. After many attempts, there should be some baseline
error level that cannot be overcome, which presumably
is "physiological"  perception error.

Dominic


      

From dlwebb at canit.se  Wed May  6 03:11:14 2009
From: dlwebb at canit.se (Dominic-Luc Webb)
Date: Tue, 5 May 2009 20:11:14 +0200 (MET DST)
Subject: [ATM] Color perception   was  Working with thin mirrors
In-Reply-To: <708469.48327.qm@web110811.mail.gq1.yahoo.com>
Message-ID: <Pine.LNX.4.44.0905052000030.16309-100000@uno.canit.se>

On Tue, 5 May 2009, Charles Broward wrote:

> Dominic,  I think you are right,  and I will make myself a study of one...

Of course, about that baseline error, I think it needs to be
consistent error at same colors to be physiological. Interest
level and determination will shift the result quite a bit,
but need not follow any particular color. I got 30-35 the
few tries, but the errors occured within entirely
different spectra. This means that despite a consistent
trained score of 30-35, I am able to get 0 across entire
spectrum sooner or later, provided I ever find this worth
my time to achieve. Maybe easier/better to settle with 30-35
and go do something else more productive, recognizing
early on that this is well within normal range.

Dominic


From rmay at nethere.com  Wed May  6 05:34:34 2009
From: rmay at nethere.com (Bob May)
Date: Tue, 5 May 2009 13:34:34 -0700
Subject: [ATM] Color perception   was  Working with thin mirrors
References: <0D65F30AA78247BC9D48FE36837719B0@D85SJB21>
Message-ID: <001b01c9cdc1$0b39f660$8f78fea9@amd>

Took a look at the test but couldn't get it to run.  Probably the
way that I've got my computer setup to keep viruses out.  I don't
allow activeX or Java to run.
It is an interesting test tho, matching the moving block to the
upper ones.
I could cheat and check the color's RGB values tho.
I can also see that the 4the band is going to be the fun one as
there are several colors that are very close to the right one.
Bob May

rmay at nethere.com
http: slash /nav.to slash bobmay
http: slash /bobmay dot astronomy.net



From rmay at nethere.com  Wed May  6 05:46:50 2009
From: rmay at nethere.com (Bob May)
Date: Tue, 5 May 2009 13:46:50 -0700
Subject: [ATM] Okie-Tex 2009 and Grinding a 14-16"
References: <907997.65251.qm@web81906.mail.mud.yahoo.com>
Message-ID: <004c01c9cdc2$b9248e60$8f78fea9@amd>

The grinding, polishing and figuring can be done in that time
frame.  Unless you get a rush order on the aluminizing, I doubt
that you'll get there.
You can always leave it bare or get a silvering kit (the Peacock
system works well) for a "first light" on the scope will probably
be the way to go.
With a bare mirror, you won't see all that much but you can get
evaluations of how good the telescope is from the other viewers.
I always recommend that the telescope be built and the mirror
evaluated for quality before aluminizing as this will insure that
you do indeed have a good mirror wiht the mirrors done at the
grinding class.
Bob May

rmay at nethere.com
http: slash /nav.to slash bobmay
http: slash /bobmay dot astronomy.net



From blaktony86 at yahoo.com  Wed May  6 06:01:45 2009
From: blaktony86 at yahoo.com (TONY B)
Date: Tue, 05 May 2009 16:01:45 CDT
Subject: [ATM] Okie-Tex 2009 and Grinding a 14-16"
Message-ID: <mailman.490.1241557308.7676.atm@atmlist.net>

  Yeah i have silvered in the past, so that is a viable option. I will defintley think about my options here. Thanks for the advice. -Tony
-----Original Message-----
Date: Tuesday, May 05, 2009 3:45:19 pm
To: <atm at atmlist.net>
From: "Bob May" <rmay at nethere.com>
Subject: Re: [ATM] Okie-Tex 2009 and Grinding a 14-16"

The grinding, polishing and figuring can be done in that time
frame.  Unless you get a rush order on the aluminizing, I doubt
that you'll get there.
You can always leave it bare or get a silvering kit (the Peacock
system works well) for a "first light" on the scope will probably
be the way to go.
With a bare mirror, you won't see all that much but you can get
evaluations of how good the telescope is from the other viewers.
I always recommend that the telescope be built and the mirror
evaluated for quality before aluminizing as this will insure that
you do indeed have a good mirror wiht the mirrors done at the
grinding class.
Bob May

rmay at nethere.com
http: slash /nav.to slash bobmay
http: slash /bobmay dot astronomy.net


_______________________________________________
ATM mailing list http://www.atmlist.net/



From hrd9 at juno.com  Wed May  6 06:14:27 2009
From: hrd9 at juno.com (horace r davis)
Date: Tue, 5 May 2009 17:14:27 -0400
Subject: [ATM] casting up date
Message-ID: <20090505.171427.3888.3.hrd9@juno.com>

I have shipped my first 15" blank to Tom Stokes in CA to day. Will be
waiting for tom to check the annealing before I make another Pyrex blank.
I will be working on building my M-O-M 20 in the mean time. I want to
thank every one for there help. I can cast soda lime blanks made from
corning glass at this time. I have nailed the annealing on that type of
glass.
____________________________________________________________
Click now and enjoy a fantastic vacation in the wine country.
http://thirdpartyoffers.juno.com/TGL2141/fc/BLSrjpTHhwh5NGl5iLHlqMV1QgZb9ltZ6umx5Gg6dKbhCMgY1XJODmn61GY/

From holmmarkd at gmail.com  Wed May  6 09:06:03 2009
From: holmmarkd at gmail.com (Mark Holm)
Date: Tue, 05 May 2009 20:06:03 -0400
Subject: [ATM] Color perception   was  Working with thin mirrors
In-Reply-To: <C8DD75DE849F410C9EE4F666667701E3@JeanGuyPC>
References: <813285.3747.qm@web90406.mail.mud.yahoo.com>
	<C8DD75DE849F410C9EE4F666667701E3@JeanGuyPC>
Message-ID: <4A00D46B.70003@gmail.com>

8,   Male, 53 years old.  My only difficulty appeared to be in the cyan 
range.  Generally, my vision is pretty good, expect for presbyopia.

-- 
Mark Holm
markholm at verizon.net
holmmarkd at gmail.com


From holmmarkd at gmail.com  Wed May  6 09:08:31 2009
From: holmmarkd at gmail.com (Mark Holm)
Date: Tue, 05 May 2009 20:08:31 -0400
Subject: [ATM] Color perception   was  Working with thin mirrors
In-Reply-To: <001b01c9cdc1$0b39f660$8f78fea9@amd>
References: <0D65F30AA78247BC9D48FE36837719B0@D85SJB21>
	<001b01c9cdc1$0b39f660$8f78fea9@amd>
Message-ID: <4A00D4FF.5050607@gmail.com>

I couldn't get it to run in Firefox, even with scripts unblocked.  Had 
to go to IE.


Bob May wrote:
> Took a look at the test but couldn't get it to run.  Probably the
> way that I've got my computer setup to keep viruses out.  I don't
> allow activeX or Java to run.
> It is an interesting test tho, matching the moving block to the
> upper ones.
> I could cheat and check the color's RGB values tho.
> I can also see that the 4the band is going to be the fun one as
> there are several colors that are very close to the right one.
> Bob May
>
> rmay at nethere.com
> http: slash /nav.to slash bobmay
> http: slash /bobmay dot astronomy.net
>
>
> _______________________________________________
> ATM mailing list http://www.atmlist.net/
>   


-- 
Mark Holm
markholm at verizon.net
holmmarkd at gmail.com


From holmmarkd at gmail.com  Wed May  6 09:18:27 2009
From: holmmarkd at gmail.com (Mark Holm)
Date: Tue, 05 May 2009 20:18:27 -0400
Subject: [ATM] Color perception   was  Working with thin mirrors
In-Reply-To: <CF182159-5BAF-4A45-A379-C290802068F7@xs4all.nl>
References: <853385.14774.qm@web54503.mail.re2.yahoo.com>	<844019.19585.qm@web81903.mail.mud.yahoo.com>	<008701c9cd34$78b06770$6a113650$@com>
	<CF182159-5BAF-4A45-A379-C290802068F7@xs4all.nl>
Message-ID: <4A00D753.70005@gmail.com>

Trust me on this one.  Buy three or four pairs.  Put one on a cord to 
wear around your neck, but leave the others around the house in likely 
places and one in your coat pocket.  I was getting awful eyestrain from 
the computer until I started using reading glasses.  Also, get a 
slightly weak pair for the computer and a slightly stronger pair for 
reading books.  It's a good idea to get some really strong ones for 
closeup work too.  They work like weak magnifiers and let you get in 
nice and close.  I finally got some prescription trifocals.  The middle 
band is just right for the computer and the bottom is great for fine 
print or low light.  Only problem is that my left eye drifted off the 
prescription within about 6 months after I got the glasses.  Now the 
distant vision is better without them on because of that.  Its hard to 
chase a moving target (my left eye lens) with inflexible glass (actually 
plastic) lenses.

Marinus van der Lugt wrote:
> Score 0, age 49, on an Apple Cinema LCD, brightness turned all the way 
> up.
>
> Unfortunately I have to buy myself a pair of reading glasses real soon 
> now :-(
> _______________________________________________
> ATM mailing list http://www.atmlist.net/


-- 
Mark Holm
markholm at verizon.net
holmmarkd at gmail.com


From wkitty42 at windstream.net  Wed May  6 14:50:37 2009
From: wkitty42 at windstream.net (waldo kitty)
Date: Wed, 06 May 2009 01:50:37 -0400
Subject: [ATM] Color perception   was  Working with thin mirrors
In-Reply-To: <001b01c9cdc1$0b39f660$8f78fea9@amd>
References: <0D65F30AA78247BC9D48FE36837719B0@D85SJB21>
	<001b01c9cdc1$0b39f660$8f78fea9@amd>
Message-ID: <4A01252D.4050307@windstream.net>

Bob May wrote:
> Took a look at the test but couldn't get it to run.  Probably the
> way that I've got my computer setup to keep viruses out.  I don't
> allow activeX or Java to run.

i do the same, bob but can easily turn on or otherwise allow them for certain 
sites... there's nothing on that site that can get you... nothing that my manual 
or automated reviews caught anyway and my protections didn't squeal out when i 
did allow the site's java stuff to run to be able to take the test...

> It is an interesting test tho, matching the moving block to the
> upper ones.

hunh? no... you get 4 bars of colors and adjust the squares in each bar to their 
proper place within each bar so they are in order from the left hue to the right 
hue... dunno what you are/were seeing with a moving block and matching it to any 
"upper" ones :?

> I could cheat and check the color's RGB values tho.
> I can also see that the 4the band is going to be the fun one as
> there are several colors that are very close to the right one.

yep... i missed 5 in the middle of each of the four giving me a 20 score... 
dunno why (yet) as my monitor is calibrated but may have drifted since that 
calibration...

-- 
NOTE: NEW EMAIL ADDRESS!!

        _\/
       (@@)                      Waldo Kitty, Waldo's Place USA
__ooO_( )_Ooo_____________________ telnet://bbs.wpusa.dynip.com
_|_____|_____|_____|_____|_____|_____ http://www.wpusa.dynip.com
____|_____|_____|_____|_____|_____|____ ftp://ftp.wpusa.dynip.com
_|_Eat_SPAM_to_email_me!_YUM!__|_____ wkitty42 -at- windstream.net

From wkitty42 at windstream.net  Wed May  6 14:55:13 2009
From: wkitty42 at windstream.net (waldo kitty)
Date: Wed, 06 May 2009 01:55:13 -0400
Subject: [ATM] Color perception   was  Working with thin mirrors
In-Reply-To: <4A00D4FF.5050607@gmail.com>
References: <0D65F30AA78247BC9D48FE36837719B0@D85SJB21>	<001b01c9cdc1$0b39f660$8f78fea9@amd>
	<4A00D4FF.5050607@gmail.com>
Message-ID: <4A012641.5010806@windstream.net>

Mark Holm wrote:
> I couldn't get it to run in Firefox, even with scripts unblocked.  Had 
> to go to IE.

totally wierd as i only use firefox... got the last of the v2.x on this machine 
and the latest v3.x on several others... only needed to tell noscript to 
temporarily allow that site... adblock didn't have anything blocked that i know 
of and my other protections, several of them between me and the net as well as 
local on the machine, didn't raise any red flags or warnings...

-- 
NOTE: NEW EMAIL ADDRESS!!

        _\/
       (@@)                      Waldo Kitty, Waldo's Place USA
__ooO_( )_Ooo_____________________ telnet://bbs.wpusa.dynip.com
_|_____|_____|_____|_____|_____|_____ http://www.wpusa.dynip.com
____|_____|_____|_____|_____|_____|____ ftp://ftp.wpusa.dynip.com
_|_Eat_SPAM_to_email_me!_YUM!__|_____ wkitty42 -at- windstream.net

From toolontop at yahoo.com  Wed May  6 16:16:47 2009
From: toolontop at yahoo.com (Mark Cowan)
Date: Wed, 6 May 2009 00:16:47 -0700 (PDT)
Subject: [ATM] Color perception   was  Working with thin mirrors
Message-ID: <255968.82616.qm@web90406.mail.mud.yahoo.com>


This is an interesting test, and it does have a learning curve of sorts, but it's not necessarily testing what it claims to be doing.  It's testing as well what kind of monitor you're using (see below)  And it's testing just how frustrated you're willing to become before giving up and figuring out WHY it's frustrating. ;)

The truth came out when I stopped playing with the new 22" Asus 1080p (TN LCD) monitor's settings and swapping colors around in IrfanView (to sort out the differences) and just took a screenshot and started looking at it on other machines. 

On the Dell 17" LCD that's going on a testing rig it looked about the same, if rather murky.  But when I popped it up on the older 15" Dell LCD that's part of the new grinding machine the light dawned (literally).  It was EASY to see the mismatches there, and they jumped right out even with shop dust covering it.  This monitor happens to have an IPS screen (with consistent wide viewing angle), as opposed to the TN screens on the other two (with color shifts from side to side).  I'm assuming it's 8-bit as well, the newer inexpensive screens are all 6-bit for speed - and on a test like this it really bites!  I'm planning to replace the Asus with a high-gamut HP with an H-IPS screen for those very reasons, as it almost make me miss my 17" Trinitron with the anti-glare coating removed via razor blade. ;)

It'll be interesting to see what the difference is with this test and the new monitor after calibration.  But I'm thinking most people would find it easier with proper color chips to shuffle instead under a full spectrum light source (like, uhm, the sun).  And I do get asked to color match clothing... :)  

Best,
Mark

--- On Tue, 5/5/09, Dominic-Luc Webb <dlwebb at canit.se> wrote:

> From: Dominic-Luc Webb <dlwebb at canit.se>
> Subject: Re: [ATM] Color perception   was  Working with thin mirrors
> To: "ATM Superheros" <atm at atmlist.net>
> Date: Tuesday, May 5, 2009, 7:05 AM
> 
> I think it should be clear this has a learning curve. Work
> this exercise every day and you will quickly improve. A
> similar thing happens on the first efforts to estimate
> magnitudes, and that quickly improves. Inspect that chart
> afterwards and you will recognize differences between
> adjacent colors that need to be re-arranged. The entire
> gradient becomes familiar as your brain sorts out adjacent
> squares one at a time. From the start, it may not be clear
> visually what constitutes correct ordering, but as you are
> provided cues about correct answer, you re-sort. I think
> this really means that most of us have good perception,
> but
> the rules and amount of scrutiny needed for correct
> ordering must first be learned.
> 
> It seems to me that the true measure for any individual
> would be the mean score after overcoming the learning
> curve. After many attempts, there should be some baseline
> error level that cannot be overcome, which presumably
> is "physiological"? perception error.
> 
> Dominic
> 
> _______________________________________________
> ATM mailing list http://www.atmlist.net/
> 


      

From simo at simoivanov.com  Wed May  6 17:14:42 2009
From: simo at simoivanov.com (simo ivanov)
Date: Wed, 06 May 2009 17:14:42 +0900
Subject: [ATM] Color perception   was  Working with thin mirrors
In-Reply-To: <4A00D4FF.5050607@gmail.com>
References: <0D65F30AA78247BC9D48FE36837719B0@D85SJB21>	<001b01c9cdc1$0b39f660$8f78fea9@amd>
	<4A00D4FF.5050607@gmail.com>
Message-ID: <4A0146F2.4010706@simoivanov.com>

You need both javascript and cookies enabled. Worked fine for me in 3.0
and 3.1beta.

Monitors and ambient lighing matter a lot for this test - I got a 32 on
an uncalibrated monitor in bright sunlight, then scored pefrect on a
calibrated monitor in a well-lit room in the evening.

late 30s, bad astigmatism.




Mark Holm wrote:
> I couldn't get it to run in Firefox, even with scripts unblocked.  Had
> to go to IE.
> 
> 
> Bob May wrote:
>> Took a look at the test but couldn't get it to run.  Probably the
>> way that I've got my computer setup to keep viruses out.  I don't
>> allow activeX or Java to run.
>> It is an interesting test tho, matching the moving block to the
>> upper ones.
>> I could cheat and check the color's RGB values tho.
>> I can also see that the 4the band is going to be the fun one as
>> there are several colors that are very close to the right one.
>> Bob May
>>
>> rmay at nethere.com
>> http: slash /nav.to slash bobmay
>> http: slash /bobmay dot astronomy.net
>>
>>
>> _______________________________________________
>> ATM mailing list http://www.atmlist.net/
>>   
> 
> 


From lugt at xs4all.nl  Wed May  6 18:17:31 2009
From: lugt at xs4all.nl (Marinus van der Lugt)
Date: Wed, 6 May 2009 11:17:31 +0200 (CEST)
Subject: [ATM] Color perception   was  Working with thin mirrors
Message-ID: <4746.87.255.50.71.1241601451.squirrel@webmail.xs4all.nl>

> It's testing as well what kind of monitor you're using

Absolutely.
I estimate that anybody scoring 30-40 has in fact perfect color vision and
is just reporting on the state of his monitor and illumination conditions.

(I cannot reproduce my 0 score from my cinema display on my laptop
display. But on the cinema display the difference really stands out.)


From ericandroberta at sbcglobal.net  Thu May  7 03:11:52 2009
From: ericandroberta at sbcglobal.net (D ERIC ALLEN)
Date: Wed, 6 May 2009 11:11:52 -0700 (PDT)
Subject: [ATM] color perception
Message-ID: <873778.43183.qm@web80502.mail.mud.yahoo.com>

Hi everybody.? Returning after several years absence.? I'm retired now, so maybe I can keep up with it this time.? I took the color test (LCD monitor) and got a seven.? I'm 64 (almost).? My problem is low light color blindness.? I've never seen color in the Orion Nebula?at a dark sky site.? However, It?had a distinct lime green color once while observing from my suburban front yard.? I guess the ambient light was enough to turn on my color receptors.? As far as aperture differences go, I see color in Jupiter in my 17.5", but not in my 5".? Don't know if it's the aperture difference or the low light problem.
I will have lots of questions for the list as soon as I finish the primary for my 24" f/4-f/12 Classical Cass.? Been working on it for ages, but I'm almost finished.
Good to be back.
Eric

From nilsolof.carlin at telia.com  Thu May  7 04:00:09 2009
From: nilsolof.carlin at telia.com (Nils Olof Carlin)
Date: Wed, 6 May 2009 21:00:09 +0200
Subject: [ATM] Color perception   was  Working with thin mirrors
References: <813285.3747.qm@web90406.mail.mud.yahoo.com><C8DD75DE849F410C9EE4F666667701E3@JeanGuyPC><1DEF316C558843488938785A8222C463@donaldp4>
	<4908B5875C3C4FC189ECB74DA776407B@niks03981037eb>
Message-ID: <830FA9185E934F4097BEBA39C8344BB3@dittda7685d135>

My data point: score=16 with 66 year old eyes , with a 5 year old LCD 
monitor. And progressive glasses - better than the proverbial sliced bread, 
for me who who is fortunate enough to adapt to them, though not everybody 
can get used to them. But at 12 grams total for this version, they are a 
light load - maybe a choice for Marinus?

>> Take a test at :
>>
>> http://www.xrite.com/custom_page.aspx?PageID=77


From blaktony86 at yahoo.com  Thu May  7 04:33:40 2009
From: blaktony86 at yahoo.com (TONY BLAKESLEY)
Date: Wed, 6 May 2009 12:33:40 -0700 (PDT)
Subject: [ATM] beveling edge during figuring stage
Message-ID: <469487.67570.qm@web81905.mail.mud.yahoo.com>

Hello,
?
I am in my final stages of figuring but this annoying little chip/bubble is catching on the pitch at the extreme edge of the mirror. As of now, there is maybe a 1/32" bevel. This tiny chip is making my figuring strokes less perfect and its showing up on the Ronchi Test. The ronchigram shows a tiny little pit at the extreme edge on the bevel and some wierd marks. The ronchi lines dont skew around it but you can just barely see a noticeable surface distoration because of the chip. 
?
Would it be safe to bevel the edge this late in the game? I would rather not go back to fine grinding as I am getting close to a nice figure. If I increase the bevel to 1/16" or 1/8" the chip will be gone. Is it worth risk scratching the mirror to bevel the mirror or should I leave it alone?
?
Thanks,

Tony

From hermit at outofoptions.org  Thu May  7 04:44:26 2009
From: hermit at outofoptions.org (hermit)
Date: Wed, 06 May 2009 15:44:26 -0400
Subject: [ATM] beveling edge during figuring stage
In-Reply-To: <469487.67570.qm@web81905.mail.mud.yahoo.com>
References: <469487.67570.qm@web81905.mail.mud.yahoo.com>
Message-ID: <4A01E89A.20300@outofoptions.org>

TONY BLAKESLEY wrote:
> Hello,
>  
> I am in my final stages of figuring but this annoying little chip/bubble is catching on the pitch at the extreme edge of the mirror. As of now, there is maybe a 1/32" bevel. This tiny chip is making my figuring strokes less perfect and its showing up on the Ronchi Test. The ronchigram shows a tiny little pit at the extreme edge on the bevel and some wierd marks. The ronchi lines dont skew around it but you can just barely see a noticeable surface distoration because of the chip. 
>  
> Would it be safe to bevel the edge this late in the game? I would rather not go back to fine grinding as I am getting close to a nice figure. If I increase the bevel to 1/16" or 1/8" the chip will be gone. Is it worth risk scratching the mirror to bevel the mirror or should I leave it alone?
>  
>   
This is a tough one to answer, but it should not cause a problem in 
figuring.  You can bevel now if it makes  you feel better though.  It 
shouldn't hurt anything.  The only way the chip should matter is if it 
has an edge that sticks up into the lap or your lap is way too soft.  It 
would have to be pretty soft though.  Like, just poured it soft.

A picture might help.

Ken Lowther

From rmay at nethere.com  Thu May  7 05:30:00 2009
From: rmay at nethere.com (Bob May)
Date: Wed, 6 May 2009 13:30:00 -0700
Subject: [ATM] Color perception   was  Working with thin mirrors
References: <288180.30192.qm@web54504.mail.re2.yahoo.com>
Message-ID: <000901c9ce89$6f15a260$8f78fea9@amd>

Them maybe I don't understand how to do the test.  I hit the
similar looking color in the top row to what the lower row is and
nothing moved.  Tried moving the lower single block to where I
thought the match was an no change.  Tried clicking the correct
block and below the correct block and still no changes.  Tried it
and failed to do anything.  I'm bored of it now.
Bob May

rmay at nethere.com
http: slash /nav.to slash bobmay
http: slash /bobmay dot astronomy.net



From rmay at nethere.com  Thu May  7 05:46:31 2009
From: rmay at nethere.com (Bob May)
Date: Wed, 6 May 2009 13:46:31 -0700
Subject: [ATM] Color perception   was  Working with thin mirrors
References: <0D65F30AA78247BC9D48FE36837719B0@D85SJB21><001b01c9cdc1$0b39f660$8f78fea9@amd>
	<4A01252D.4050307@windstream.net>
Message-ID: <001e01c9ce8b$bd5af2c0$8f78fea9@amd>

Not the way I read the instructions!  I won't run Javascript so
it is a moot point now.
Bob May

rmay at nethere.com
http: slash /nav.to slash bobmay
http: slash /bobmay dot astronomy.net



From rmay at nethere.com  Thu May  7 06:14:00 2009
From: rmay at nethere.com (Bob May)
Date: Wed, 6 May 2009 14:14:00 -0700
Subject: [ATM] color perception
References: <873778.43183.qm@web80502.mail.mud.yahoo.com>
Message-ID: <002f01c9ce8f$9471c920$8f78fea9@amd>

It all depends upon the size of telescope you're using.  There
are slight differences betweeen people as to when the color
recptors are starting to get activated, just like the limit for
monochrome.
Bob May

rmay at nethere.com
http: slash /nav.to slash bobmay
http: slash /bobmay dot astronomy.net



From rmay at nethere.com  Thu May  7 06:16:05 2009
From: rmay at nethere.com (Bob May)
Date: Wed, 6 May 2009 14:16:05 -0700
Subject: [ATM] beveling edge during figuring stage
References: <469487.67570.qm@web81905.mail.mud.yahoo.com>
Message-ID: <003201c9ce8f$dec3f840$8f78fea9@amd>

Just bevel in the area of the hole till the hole goes away.
don't worry about the rest.
Just don't brush the surface of the galss or you may make a
scratch.  Clean carefully as you would with the completed mirror.
Bob May

rmay at nethere.com
http: slash /nav.to slash bobmay
http: slash /bobmay dot astronomy.net



From wa4guu at verizon.net  Thu May  7 06:18:59 2009
From: wa4guu at verizon.net (Jerry)
Date: Wed, 06 May 2009 17:18:59 -0400
Subject: [ATM] beveling edge during figuring stage
In-Reply-To: <469487.67570.qm@web81905.mail.mud.yahoo.com>
Message-ID: <D62DAD6F597C497F8991E645759568CC@D85SJB21>

Hello Tony,

I would not recommend beveling at this stage. You are likely to make a lot
of small clamshells chips at the edge.

If you have polished into a bubble the weird marks you see can be similar to
a turned edge except that it is the edge of the bubble that is turning. You
may see some grooves coming out of it and maybe you can even see it directly
by looking at a reflected lamp.

If it is a bubble you can stop the turning and grooves coming out of it by
filling the bubble with pitch. Hard pitch would probably be better but for a
small bubble it might not make a difference. You can boil a teaspoon of
pitch to make it harder. While it is still warm take a small bead and push
it into the bubble. Level it off as best you can.

Go back to work. It should start getting better pretty quick.

Jerry


-----Original Message-----
From: atm-bounces at atmlist.net [mailto:atm-bounces at atmlist.net] On Behalf Of
TONY BLAKESLEY
Sent: Wednesday, May 06, 2009 3:34 PM
To: atm at atmlist.net
Subject: [ATM] beveling edge during figuring stage

Hello,
?
I am in my final stages of figuring but this annoying little chip/bubble is
catching on the pitch at the extreme edge of the mirror. As of now, there is
maybe a 1/32" bevel. This tiny chip is making my figuring strokes less
perfect and its showing up on the Ronchi Test. The ronchigram shows a tiny
little pit at the extreme edge on the bevel and some wierd marks. The ronchi
lines dont skew around it but you can just barely see a noticeable surface
distoration because of the chip. 
?
Would it be safe to bevel the edge this late in the game? I would rather not
go back to fine grinding as I am getting close to a nice figure. If I
increase the bevel to 1/16" or 1/8" the chip will be gone. Is it worth risk
scratching the mirror to bevel the mirror or should I leave it alone?
?
Thanks,

Tony
_______________________________________________
ATM mailing list http://www.atmlist.net/


From mbartels at bbastrodesigns.com  Thu May  7 08:41:06 2009
From: mbartels at bbastrodesigns.com (Mel Bartels)
Date: Wed, 6 May 2009 16:41:06 -0700
Subject: [ATM] beveling edge during figuring stage
In-Reply-To: <469487.67570.qm@web81905.mail.mud.yahoo.com>
References: <469487.67570.qm@web81905.mail.mud.yahoo.com>
Message-ID: <00af01c9cea4$26a3d7c0$73eb8740$@com>

>>>
Would it be safe to bevel the edge this late in the game? I would rather not
go back to fine grinding as I am getting close to a nice figure. If I
increase the bevel to 1/16" or 1/8" the chip will be gone. Is it worth risk
scratching the mirror to bevel the mirror or should I leave it alone?
<<<

I recommend to the students in my mirror making classes to always maintain
the bevel.  I've never seen anyone scratch the mirror even after fine
grinding.  Do downward slanted strokes with the grinding stone or diamond
tool.

Mel Bartels



From rozer at pacbell.net  Thu May  7 12:27:41 2009
From: rozer at pacbell.net (Richard Ozer)
Date: Wed, 6 May 2009 20:27:41 -0700
Subject: [ATM] beveling edge during figuring stage
In-Reply-To: <00af01c9cea4$26a3d7c0$73eb8740$@com>
References: <469487.67570.qm@web81905.mail.mud.yahoo.com>
	<00af01c9cea4$26a3d7c0$73eb8740$@com>
Message-ID: <4A02552D.9000300@pacbell.net>

At the Chabot workshop, we make the same recommendation as Mel.  
Beveling is safe to do at any stage as long as it's done carefully.  
Rinse well after beveling...

Rich Ozer

Mel Bartels wrote:
> Would it be safe to bevel the edge this late in the game? I would rather not
> go back to fine grinding as I am getting close to a nice figure. If I
> increase the bevel to 1/16" or 1/8" the chip will be gone. Is it worth risk
> scratching the mirror to bevel the mirror or should I leave it alone?
> <<<
>
> I recommend to the students in my mirror making classes to always maintain
> the bevel.  I've never seen anyone scratch the mirror even after fine
> grinding.  Do downward slanted strokes with the grinding stone or diamond
> tool.
>
> Mel Bartels
>
>
> _______________________________________________
> ATM mailing list http://www.atmlist.net/
>
>   

From baldjeff at comcast.net  Thu May  7 14:16:17 2009
From: baldjeff at comcast.net (Jeff Baldwin)
Date: Wed, 6 May 2009 22:16:17 -0700
Subject: [ATM] Lookinglass
Message-ID: <7068BFE6CE38463D916FEB113DB259A0@glendaspc>

Hi ATMers;
My friend has been trying to contact lookinglass, a mirror blank supplier, and has not been able to make contact. They have a link on the Stellafane web-site, but the e-mails never get replies. Does anybody know this supplier/person? If so could you contact me off the bandwidth and let me know how to contact them?
Thanks all.
Bald

Jeff and Glenda Baldwin
Lathrop, CA
www.agetawaylogcabin.com
www.stocktonastro.org

From mjc5 at psu.edu  Thu May  7 20:53:27 2009
From: mjc5 at psu.edu (Michael Coslo)
Date: Thu, 07 May 2009 07:53:27 -0400
Subject: [ATM] color perception
In-Reply-To: <002f01c9ce8f$9471c920$8f78fea9@amd>
References: <873778.43183.qm@web80502.mail.mud.yahoo.com>
	<002f01c9ce8f$9471c920$8f78fea9@amd>
Message-ID: <35899AA9-6970-4839-9749-CD308E65F7BC@psu.edu>


On May 6, 2009, at 5:14 PM, Bob May wrote:

> It all depends upon the size of telescope you're using.  There
> are slight differences between people as to when the color
> recptors are starting to get activated, just like the limit for
> monochrome.

Not only that, but it varies from eye to eye on the same person. My  
left eye is more sensitive to light, and my right eye has better color  
acuity. So I have a deep space eyeball, and a planetary one. And I do  
use them in that fashion

-73 de Mike N3LI -



From stainless_steel at suddenlink.net  Thu May  7 21:26:59 2009
From: stainless_steel at suddenlink.net (stainless_steel at suddenlink.net)
Date: Thu, 7 May 2009 07:26:59 -0500
Subject: [ATM] beveling edge during figuring stage
In-Reply-To: <469487.67570.qm@web81905.mail.mud.yahoo.com>
References: <469487.67570.qm@web81905.mail.mud.yahoo.com>
Message-ID: <0A9AC10B576A46538358769F7E599CF7@R101>

Personally,

I would leave it there, leave it alone. A beveled chip would not be any 
prettier than an unbeveled chip. Just think of the rest of the mirror, what 
a fine job it will do. After you get it coated, put a little dab of black 
enamel paint on the little chip, if it bothers you. My two cents.

DLZ-130


----- Original Message ----- 
From: "TONY BLAKESLEY" <blaktony86 at yahoo.com>
To: <atm at atmlist.net>
Sent: Wednesday, May 06, 2009 2:33 PM
Subject: [ATM] beveling edge during figuring stage


Hello,

I am in my final stages of figuring but this annoying little chip/bubble is 
catching on the pitch at the extreme edge of the mirror. As of now, there is 
maybe a 1/32" bevel. This tiny chip is making my figuring strokes less 
perfect and its showing up on the Ronchi Test. The ronchigram shows a tiny 
little pit at the extreme edge on the bevel and some wierd marks. The ronchi 
lines dont skew around it but you can just barely see a noticeable surface 
distoration because of the chip.

Would it be safe to bevel the edge this late in the game? I would rather not 
go back to fine grinding as I am getting close to a nice figure. If I 
increase the bevel to 1/16" or 1/8" the chip will be gone. Is it worth risk 
scratching the mirror to bevel the mirror or should I leave it alone?

Thanks,

Tony
_______________________________________________
ATM mailing list http://www.atmlist.net/


--------------------------------------------------------------------------------



No virus found in this incoming message.
Checked by AVG - www.avg.com
Version: 8.5.325 / Virus Database: 270.12.21/2102 - Release Date: 05/07/09 
05:57:00


From stainless_steel at suddenlink.net  Thu May  7 21:32:54 2009
From: stainless_steel at suddenlink.net (stainless_steel at suddenlink.net)
Date: Thu, 7 May 2009 07:32:54 -0500
Subject: [ATM] beveling edge during figuring stage
In-Reply-To: <4A02552D.9000300@pacbell.net>
References: <469487.67570.qm@web81905.mail.mud.yahoo.com><00af01c9cea4$26a3d7c0$73eb8740$@com>
	<4A02552D.9000300@pacbell.net>
Message-ID: <BE8BCCBC67E44E37B2DF55D07D29EE7B@R101>

If you are going to opt for further bevel, hold the stone at the 45 degree 
angle, but stroke nearly tangent (say, ten degrees) to the edge of the 
mirror.

You avoid a rougher edge that way, and it practically guarantees no more 
seeds or scallops. The edge is not strong; it does not resist well a 
downward stroke; make the stroke nearly (not exactly) tangent to the mirror, 
but hold the stone at the 45 degree angle. It will bevel, without stroking 
downwards. You will get a perfect, flaw free bevel. Finish with the other 
side of the stone (the finer grit side).

DLZ-130


----- Original Message ----- 
From: "Richard Ozer" <rozer at pacbell.net>
To: "ATM" <atm at atmlist.net>
Sent: Wednesday, May 06, 2009 10:27 PM
Subject: Re: [ATM] beveling edge during figuring stage


> At the Chabot workshop, we make the same recommendation as Mel.
> Beveling is safe to do at any stage as long as it's done carefully.
> Rinse well after beveling...
>
> Rich Ozer
>
> Mel Bartels wrote:
>> Would it be safe to bevel the edge this late in the game? I would rather 
>> not
>> go back to fine grinding as I am getting close to a nice figure. If I
>> increase the bevel to 1/16" or 1/8" the chip will be gone. Is it worth 
>> risk
>> scratching the mirror to bevel the mirror or should I leave it alone?
>> <<<
>>
>> I recommend to the students in my mirror making classes to always 
>> maintain
>> the bevel.  I've never seen anyone scratch the mirror even after fine
>> grinding.  Do downward slanted strokes with the grinding stone or diamond
>> tool.
>>
>> Mel Bartels
>>
>>
>> _______________________________________________
>> ATM mailing list http://www.atmlist.net/
>>
>>
> _______________________________________________
> ATM mailing list http://www.atmlist.net/


--------------------------------------------------------------------------------



No virus found in this incoming message.
Checked by AVG - www.avg.com
Version: 8.5.325 / Virus Database: 270.12.21/2102 - Release Date: 05/07/09 
05:57:00


From Mitch_Bisnauth at Cknainc.com  Thu May  7 22:01:25 2009
From: Mitch_Bisnauth at Cknainc.com (Mitch_Bisnauth at Cknainc.com)
Date: Thu, 7 May 2009 08:01:25 -0500
Subject: [ATM] beveling edge during figuring stage
In-Reply-To: <469487.67570.qm@web81905.mail.mud.yahoo.com>
Message-ID: <OF1757277D.743EE57B-ON862575AF.00477CF2-862575AF.0047A205@Cknainc.com>

if you do bevel...let us know what was the outcome....

MitchB



TONY BLAKESLEY <blaktony86 at yahoo.com> 
Sent by: atm-bounces at atmlist.net
05/06/2009 02:33 PM
Please respond to
blaktony86 at yahoo.com


To
atm at atmlist.net
cc

Subject
[ATM] beveling edge during figuring stage






Hello,
 
I am in my final stages of figuring but this annoying little chip/bubble 
is catching on the pitch at the extreme edge of the mirror. As of now, 
there is maybe a 1/32" bevel. This tiny chip is making my figuring strokes 
less perfect and its showing up on the Ronchi Test. The ronchigram shows a 
tiny little pit at the extreme edge on the bevel and some wierd marks. The 
ronchi lines dont skew around it but you can just barely see a noticeable 
surface distoration because of the chip. 
 
Would it be safe to bevel the edge this late in the game? I would rather 
not go back to fine grinding as I am getting close to a nice figure. If I 
increase the bevel to 1/16" or 1/8" the chip will be gone. Is it worth 
risk scratching the mirror to bevel the mirror or should I leave it alone?
 
Thanks,

Tony
_______________________________________________
ATM mailing list http://www.atmlist.net/


From wjl12 at comcast.net  Thu May  7 22:16:32 2009
From: wjl12 at comcast.net (William Lee)
Date: Thu, 7 May 2009 09:16:32 -0400
Subject: [ATM] Lookinglass
In-Reply-To: <7068BFE6CE38463D916FEB113DB259A0@glendaspc>
References: <7068BFE6CE38463D916FEB113DB259A0@glendaspc>
Message-ID: <A2364C2F-5C7A-42DD-9982-CA57269C8940@comcast.net>

I'd be interested in any info, too. Lookinglass looked like it had  
some interesting products.

On May 7, 2009, at 1:16 AM, Jeff Baldwin wrote:

> Hi ATMers;
> My friend has been trying to contact lookinglass, a mirror blank  
> supplier, and has not been able to make contact. They have a link on  
> the Stellafane web-site, but the e-mails never get replies. Does  
> anybody know this supplier/person? If so could you contact me off  
> the bandwidth and let me know how to contact them?
> Thanks all.
> Bald
>
> Jeff and Glenda Baldwin
> Lathrop, CA
> www.agetawaylogcabin.com
> www.stocktonastro.org
> _______________________________________________
> ATM mailing list http://www.atmlist.net/


From wkitty42 at windstream.net  Fri May  8 00:40:18 2009
From: wkitty42 at windstream.net (waldo kitty)
Date: Thu, 07 May 2009 11:40:18 -0400
Subject: [ATM] Color perception   was  Working with thin mirrors
In-Reply-To: <000901c9ce89$6f15a260$8f78fea9@amd>
References: <288180.30192.qm@web54504.mail.re2.yahoo.com>
	<000901c9ce89$6f15a260$8f78fea9@amd>
Message-ID: <4A0300E2.7080701@windstream.net>

Bob May wrote:
> Them maybe I don't understand how to do the test.  I hit the
> similar looking color in the top row to what the lower row is and
> nothing moved.  Tried moving the lower single block to where I
> thought the match was an no change.  Tried clicking the correct
> block and below the correct block and still no changes.  Tried it
> and failed to do anything.  I'm bored of it now.

it took me a minute to do it, too, bob... and it was slow on this machine...

in each row, the first and last blocks are the anchors... each of the blocks 
between them is movable... i had to click and hold the mouse on the block i 
wanted to move and wait a split second before i started to move it... then it 
was simply dragging the block left or right to the place i wanted it and letting 
go of the button... there is no between row movement of the blocks... only left 
and right...

this old box is only 450mhz with 256meg of ram so i can easily understand the 
slowness in picking up the block on my end...

-- 
NOTE: NEW EMAIL ADDRESS!!

        _\/
       (@@)                      Waldo Kitty, Waldo's Place USA
__ooO_( )_Ooo_____________________ telnet://bbs.wpusa.dynip.com
_|_____|_____|_____|_____|_____|_____ http://www.wpusa.dynip.com
____|_____|_____|_____|_____|_____|____ ftp://ftp.wpusa.dynip.com
_|_Eat_SPAM_to_email_me!_YUM!__|_____ wkitty42 -at- windstream.net

From inkleput at isp.com  Fri May  8 00:41:22 2009
From: inkleput at isp.com (LaLone)
Date: Thu, 07 May 2009 11:41:22 -0400
Subject: [ATM] Lightweight glass
Message-ID: <4A030122.2010208@isp.com>

Has anyone tried to lighten large glass blanks by entraining the glass 
with air bubbles instead of with some sort of honeycomb arrangement?  A 
pre-curveded glass "foam" blank could be topped with a thin layer of 
bubble free glass for grinding/polishing.  (Or a glass "foam" could be 
poured onto a pre-slumped face.)  For that matter a solid glass bottom 
could be put on it as well.

They even make lightweight concrete by entraining it with air bubbles.

No, I'm not a glass engineer nor do I play one on TV, so this might be 
the worst idea ever posted here.

JimL

From wkitty42 at windstream.net  Fri May  8 03:08:18 2009
From: wkitty42 at windstream.net (waldo kitty)
Date: Thu, 07 May 2009 14:08:18 -0400
Subject: [ATM] Lightweight glass
In-Reply-To: <4A030122.2010208@isp.com>
References: <4A030122.2010208@isp.com>
Message-ID: <4A032392.6040004@windstream.net>

LaLone wrote:
> Has anyone tried to lighten large glass blanks by entraining the glass 
> with air bubbles instead of with some sort of honeycomb arrangement?  A 
> pre-curveded glass "foam" blank could be topped with a thin layer of 
> bubble free glass for grinding/polishing.  (Or a glass "foam" could be 
> poured onto a pre-slumped face.)  For that matter a solid glass bottom 
> could be put on it as well.
> 
> They even make lightweight concrete by entraining it with air bubbles.
> 
> No, I'm not a glass engineer nor do I play one on TV, so this might be 
> the worst idea ever posted here.

someone, i forget who, is working on this very thing... they have foam glass 
blocks they are fusing a thin pre-slumped glass surface to...

[time passes]

i just searched back and found that the posts i'm thinking of are by Dave Davis, 
vorblesnak -at- peak.org... search the archives for the first part of his email 
address and i'm sure you'll locate his postings... the latest one i find on the 
foam glass subject was posted on Mar 23, 2009... the threads i've found in my 
local archive are (one per line)...

"Glass and Foam Blanks, two left" (Mar 23, 2009)
"Impossible 48 s and ???" (Mar 19, 2009)
"Polishing foam" (Mar 16, 2009)
"48 inch process" (Mar 15, 2009)
"David Davis.. 48 " disk with Glass foam backing" (Mar 15, 2009)
"48 inch info and housekeeping" (Mar 15, 2009, Mar 16, 2009)
"Suggestions" (Mar 12, 2009 - this one had a couple of subject line changes and 
raised quite a discussion)
"Glass Foam Mirror Grinding Progress" (Feb 26, 2009)
"Glass foam only a partial success" (Jan 23, 2009)
"Menicus mirrors on glass foam" (Jan 23, 2009)
"Something new for the thin meniscus mirror folks" (Jan 20, 2009)
"Is kiln work of use to amateur telescope makers" (Dec 22, 2008 - first mention 
of his work with foam glass)

-- 
NOTE: NEW EMAIL ADDRESS!!

        _\/
       (@@)                      Waldo Kitty, Waldo's Place USA
__ooO_( )_Ooo_____________________ telnet://bbs.wpusa.dynip.com
_|_____|_____|_____|_____|_____|_____ http://www.wpusa.dynip.com
____|_____|_____|_____|_____|_____|____ ftp://ftp.wpusa.dynip.com
_|_Eat_SPAM_to_email_me!_YUM!__|_____ wkitty42 -at- windstream.net

From vladimir.galogaza1 at zg.t-com.hr  Fri May  8 03:35:49 2009
From: vladimir.galogaza1 at zg.t-com.hr (Vladimir Galogaza)
Date: Thu, 7 May 2009 20:35:49 +0200
Subject: [ATM] Lightweight glass
References: <4A030122.2010208@isp.com>
Message-ID: <4085BCA3B9BF4EEBB178C764942ABC07@piv555a133b59e>

Jim,

>Has anyone tried to lighten large glass blanks by entraining the glass 
>with air bubbles instead of with some sort of honeycomb arrangement?  A 
>pre-curveded glass "foam" blank could be topped with a thin layer of 
>bubble free glass for grinding/polishing. 

The idea was tested by David Davis on foam glass.
He reported on it extensively and you can find it in archives.
Here is small quote from his mail:

> I am working with some material called foamglass.
> It is an industrial insulation made of glass that has been foamed up with
>trapped gas.  I have successfully fused a glass face onto a pre-curved
>puck of the foamglas material. 

If you are interested in details David is available at:
vorblesnak at peak.org

Regards
Vladimir.

From foreilly at bestweb.net  Fri May  8 04:27:47 2009
From: foreilly at bestweb.net (Francis J. O'Reilly)
Date: Thu, 7 May 2009 15:27:47 -0400
Subject: [ATM] beveling edge during figuring stage
References: <469487.67570.qm@web81905.mail.mud.yahoo.com>
	<0A9AC10B576A46538358769F7E599CF7@R101>
Message-ID: <8BA4A3BD9E574A32B374D200BB6958D1@D5GHLR11>

I tend to agree with David, leave it alone.

My concern would be greater if there was no bevel at all during polishing, I
like to allow a little bevel room at the edge during polishing to avoid the
potential of large chips.

Francis J. O'Reilly
----- Original Message ----- 
From: <stainless_steel at suddenlink.net>
To: <blaktony86 at yahoo.com>; <atm at atmlist.net>
Sent: Thursday, May 07, 2009 8:26 AM
Subject: Re: [ATM] beveling edge during figuring stage


> Personally,
>
> I would leave it there, leave it alone. A beveled chip would not be any
> prettier than an unbeveled chip. Just think of the rest of the mirror,
> what a fine job it will do. After you get it coated, put a little dab of
> black enamel paint on the little chip, if it bothers you. My two cents.
>
> DLZ-130
>
>
> ----- Original Message ----- 
> From: "TONY BLAKESLEY" <blaktony86 at yahoo.com>
> To: <atm at atmlist.net>
> Sent: Wednesday, May 06, 2009 2:33 PM
> Subject: [ATM] beveling edge during figuring stage
>
>
> Hello,
>
> I am in my final stages of figuring but this annoying little chip/bubble
> is catching on the pitch at the extreme edge of the mirror. As of now,
> there is maybe a 1/32" bevel. This tiny chip is making my figuring strokes
> less perfect and its showing up on the Ronchi Test. The ronchigram shows a
> tiny little pit at the extreme edge on the bevel and some wierd marks. The
> ronchi lines dont skew around it but you can just barely see a noticeable
> surface distoration because of the chip.
>
> Would it be safe to bevel the edge this late in the game? I would rather
> not go back to fine grinding as I am getting close to a nice figure. If I
> increase the bevel to 1/16" or 1/8" the chip will be gone. Is it worth
> risk scratching the mirror to bevel the mirror or should I leave it alone?
>
> Thanks,
>
> Tony
> _______________________________________________
> ATM mailing list http://www.atmlist.net/
>
>
> --------------------------------------------------------------------------------
>
>
>
> No virus found in this incoming message.
> Checked by AVG - www.avg.com
> Version: 8.5.325 / Virus Database: 270.12.21/2102 - Release Date: 05/07/09
> 05:57:00
>
> _______________________________________________
> ATM mailing list http://www.atmlist.net/


From bthomas32000 at yahoo.com  Fri May  8 04:34:00 2009
From: bthomas32000 at yahoo.com (Bill Thomas)
Date: Thu, 7 May 2009 12:34:00 -0700 (PDT)
Subject: [ATM]  beveling edge during figuring stage
Message-ID: <39850.96698.qm@web31006.mail.mud.yahoo.com>


>Hello,
 
>I am in my final stages of figuring but this annoying little chip/bubble >is catching on the pitch at the extreme edge of the mirror. As of now, >there is maybe a 1/32" bevel.

as has been suggested grind out any large chip w/t a wet stone - vary carefully.  now polish the edge using a piece of glass (instead of the stone) & CEO.  if you are using a machine e.g., M-o-M spin the table up to high speed and with the glass & CEO should not take long.  after that replace the glass w/t a stick wrapped w/t cotton bathed in CEO, being careful that the cotton not touch the mirror surface - to avoid TDE!

best practice to bevel during rough grinding w/t the stone and then switch to the glass at the finer grades and then when polishing use the stick & cotton w/t CEO.  should not be needed during figuring. when finished the 3/32" chamfered edge should be polished.

it's described in "A Manual for Amateur Telescope Makers" Lecleir page 46, 47


      

From rmay at nethere.com  Fri May  8 05:20:45 2009
From: rmay at nethere.com (Bob May)
Date: Thu, 7 May 2009 13:20:45 -0700
Subject: [ATM] Lightweight glass
References: <4A030122.2010208@isp.com>
	<4085BCA3B9BF4EEBB178C764942ABC07@piv555a133b59e>
Message-ID: <002e01c9cf51$57f144e0$8f78fea9@amd>

I've been waiting for one of David's blanks.  His latest report
was that he was shipping this week and since I'm down here in San
Diego area, it should be 3 days shipping time.  Haven't seen the
box yet but am quite anxious to see it.  Time for showing it at
RTMC is getting short for doing a polish on the blank.
Bob May

rmay at nethere.com
http: slash /nav.to slash bobmay
http: slash /bobmay dot astronomy.net



From tstokes at pacbell.net  Fri May  8 06:05:07 2009
From: tstokes at pacbell.net (Tom Stokes)
Date: Thu, 7 May 2009 14:05:07 -0700
Subject: [ATM] Polyurethane tiles
Message-ID: <92AA4ACBDFB2407AB6433852EC62F19E@tom>

Has anyone made a tile tool of Hydrostone/dental stone using polyurethane 
glue (e.g. Gorilla glue) to bond the tiles?

Tom Stokes
http://www.mirrorgrindingmachine.com/


From don.surles at verizon.net  Fri May  8 06:37:56 2009
From: don.surles at verizon.net (don surles)
Date: Thu, 07 May 2009 17:37:56 -0400
Subject: [ATM] beveling edge during figuring stage
In-Reply-To: <39850.96698.qm@web31006.mail.mud.yahoo.com>
References: <39850.96698.qm@web31006.mail.mud.yahoo.com>
Message-ID: <9e9cbc00e1aba1df6140113c740cb1d6@verizon.net>

beveling used to be  a chore for us at the MidAtlantic Mirror Making 
weekend; with only one weekend to complete a mirror the time spent 
beveling seemed a precious waster of time.  but a couple of years ago 
we found some diamond hones from Harbor Freight that makes the task 
fast and easy.  They have a $10 unit with 4 grades...200, 300, 400 & 
600.

every mirror maker should have one and retire the carbo stones.  it 
will save a couple of hours beveling time and if used properly will 
avoid the scratches that come from loose beveled glass being dragged 
across a polished surface.

Don Surles


On May 7, 2009, at 3:34 PM, Bill Thomas wrote:

>
>> Hello,
>
>> I am in my final stages of figuring but this annoying little 
>> chip/bubble >is catching on the pitch at the extreme edge of the 
>> mirror. As of now, >there is maybe a 1/32" bevel.
>
> as has been suggested grind out any large chip w/t a wet stone - vary 
> carefully.  now polish the edge using a piece of glass (instead of the 
> stone) & CEO.  if you are using a machine e.g., M-o-M spin the table 
> up to high speed and with the glass & CEO should not take long.  after 
> that replace the glass w/t a stick wrapped w/t cotton bathed in CEO, 
> being careful that the cotton not touch the mirror surface - to avoid 
> TDE!
>
> best practice to bevel during rough grinding w/t the stone and then 
> switch to the glass at the finer grades and then when polishing use 
> the stick & cotton w/t CEO.  should not be needed during figuring. 
> when finished the 3/32" chamfered edge should be polished.
>
> it's described in "A Manual for Amateur Telescope Makers" Lecleir page 
> 46, 47
>
>
>
> _______________________________________________
> ATM mailing list http://www.atmlist.net/
>
>
Don Surles


From holmmarkd at gmail.com  Fri May  8 10:30:44 2009
From: holmmarkd at gmail.com (Mark Holm)
Date: Thu, 07 May 2009 21:30:44 -0400
Subject: [ATM] [Fwd: Re:  Polyurethane tiles]
Message-ID: <4A038B44.6040401@gmail.com>




I haven't tried it, but one point to keep in mind is that Gorilla Glue 
foams as it cures, expanding.  Could give unexpected results.

Why not use the tile in stone method???  works great for a lot of us.  
It's quick, no glue to mess with and you are good to go in an hour or less.

see it here  http://gotgrit.com/make_tool1.php

Tom Stokes wrote:
> Has anyone made a tile tool of Hydrostone/dental stone using 
> polyurethane glue (e.g. Gorilla glue) to bond the tiles?
>
> Tom Stokes
> http://www.mirrorgrindingmachine.com/
>
> _______________________________________________
> ATM mailing list http://www.atmlist.net/


-- 
Mark Holm
markholm at verizon.net
holmmarkd at gmail.com



From holmmarkd at gmail.com  Fri May  8 10:35:35 2009
From: holmmarkd at gmail.com (Mark Holm)
Date: Thu, 07 May 2009 21:35:35 -0400
Subject: [ATM] Polyurethane tiles
In-Reply-To: <92AA4ACBDFB2407AB6433852EC62F19E@tom>
References: <92AA4ACBDFB2407AB6433852EC62F19E@tom>
Message-ID: <4A038C67.1020701@gmail.com>

If you join the Yahoo Group  atm_free, then look in the Files section 
under Richard Schwartz, you will find a document named     TILETOOL.doc

This has a great description of the "tile in stone" method.

As I have written before, once you try it this way, you won't ever want 
to do it any other way.

-- 
Mark Holm
markholm at verizon.net
holmmarkd at gmail.com


From russjocoy at hotmail.com  Fri May  8 10:38:35 2009
From: russjocoy at hotmail.com (Russell Jocoy)
Date: Thu, 7 May 2009 21:38:35 -0400
Subject: [ATM] Edge bevel after polish
Message-ID: <COL116-W517B8B308F2AEE26DFE3C0B8640@phx.gbl>


 

 

To all and concerned, This process is really very easy, Don't be scared about your surface.

Harbor Frieght sell's a diamond sharpener with 4 different grades of diamond grits.

  This amazing sander goes from 200 to 600 grit with no flake out. The only grit will be what you grind off. This tool is made for sharpening blades, but it shave's glass like butter.

   This can be done on a completed mirror, have no fear, bevel, wash, bevel, wash again,

Spray the shit out of your mirror with clean water, wipe, continue , relax, figure, don't

worry... You have been careful up to this process, just do it and be careful again.

   Whatever you do to the surface or the edge can be changed, and yes scratches on the surface are horror stories in a foucault image, but I have seen them disappear in a few

polishing sessions, as long as they are not "heavy" grit groove's, then you have really screwed up...back to the mine's.... Ease up the bevel can be done with care and alot of water.  Remember, wash, wash,   continue... I wash my mirror with a hose, outside..

                            Russ

_________________________________________________________________
Hotmail? has ever-growing storage! Don?t worry about storage limits.
http://windowslive.com/Tutorial/Hotmail/Storage?ocid=TXT_TAGLM_WL_HM_Tutorial_Storage1_052009

From blaktony86 at yahoo.com  Fri May  8 11:32:23 2009
From: blaktony86 at yahoo.com (TONY B)
Date: Thu, 07 May 2009 21:32:23 CDT
Subject: [ATM] Edge bevel after polish
Message-ID: <mailman.611.1241749947.7676.atm@atmlist.net>

 Wow! That is amazing... So no worry about flaking of glass? Harbor freight.. Might have to make a trip now. I just worry my edge will flake and that would kill me. So lots of water. Grind tangent to edge @ 45 degree angle, correct?
-----Original Message-----
Date: Thursday, May 07, 2009 9:03:39 pm
To: "ATM list" <atm at atmlist.net>
From: "Russell Jocoy" <russjocoy at hotmail.com>
Subject: [ATM] Edge bevel after polish


 

 

To all and concerned, This process is really very easy, Don't be scared about your surface.

Harbor Frieght sell's a diamond sharpener with 4 different grades of diamond grits.

  This amazing sander goes from 200 to 600 grit with no flake out. The only grit will be what you grind off. This tool is made for sharpening blades, but it shave's glass like butter.

   This can be done on a completed mirror, have no fear, bevel, wash, bevel, wash again,

Spray the shit out of your mirror with clean water, wipe, continue , relax, figure, don't

worry... You have been careful up to this process, just do it and be careful again.

   Whatever you do to the surface or the edge can be changed, and yes scratches on the surface are horror stories in a foucault image, but I have seen them disappear in a few

polishing sessions, as long as they are not "heavy" grit groove's, then you have really screwed up...back to the mine's.... Ease up the bevel can be done with care and alot of water.  Remember, wash, wash,   continue... I wash my mirror with a hose, outside..

                            Russ

_________________________________________________________________
Hotmail? has ever-growing storage! Don?t worry about storage limits.
http://windowslive.com/Tutorial/Hotmail/Storage?ocid=TXT_TAGLM_WL_HM_Tutorial_Storage1_052009
_______________________________________________
ATM mailing list http://www.atmlist.net/



From dlwebb at canit.se  Fri May  8 19:12:11 2009
From: dlwebb at canit.se (Dominic-Luc Webb)
Date: Fri, 8 May 2009 12:12:11 +0200 (MET DST)
Subject: [ATM] Polyurethane tiles
In-Reply-To: <92AA4ACBDFB2407AB6433852EC62F19E@tom>
Message-ID: <Pine.LNX.4.44.0905081210380.31638-100000@uno.canit.se>

On Thu, 7 May 2009, Tom Stokes wrote:

> Has anyone made a tile tool of Hydrostone/dental stone using polyurethane
> glue (e.g. Gorilla glue) to bond the tiles?

I used this to put some new tiles to replace some that fell
out of a hydrostone tool. It took only a few minutes to
carefully grind the new tile flush with the surrounding
ones. So far no trouble.

Dominic


From mjc5 at psu.edu  Fri May  8 21:33:59 2009
From: mjc5 at psu.edu (Michael Coslo)
Date: Fri, 08 May 2009 08:33:59 -0400
Subject: [ATM] [Fwd: Re:  Polyurethane tiles]
In-Reply-To: <4A038B44.6040401@gmail.com>
References: <4A038B44.6040401@gmail.com>
Message-ID: <38489013-26FA-467D-B4B9-22E0244C8893@psu.edu>


On May 7, 2009, at 9:30 PM, Mark Holm wrote:

> I haven't tried it, but one point to keep in mind is that Gorilla  
> Glue foams as it cures, expanding.  Could give unexpected results.


	Gorilla glue might not be the best choice - it's also hydrophilic.  
But I believe it will send the excess glue to the side as it cures,  
and my hydrophilic fears might be moot. Who knows, it might get  
stronger with each wet?

	But that being said Tom, I would recommend trying it, then reporting  
back to us. It just might work well.


> Why not use the tile in stone method???  works great for a lot of  
> us.  It's quick, no glue to mess with and you are good to go in an  
> hour or less.


	If I might be a little controversial here, it seems that a sort of  
"this is how it must be done" has grown around tool construction.  
Certainly I've been told about my tool construction and composition  
shortcomings.

And yet my tools have produced some fine mirrors. There is a whole  
world out there beyond dental stone.

-73 de Mike N3LI -



From blaktony86 at yahoo.com  Fri May  8 22:09:11 2009
From: blaktony86 at yahoo.com (TONY B)
Date: Fri, 08 May 2009 08:09:11 CDT
Subject: [ATM] [Fwd: Re:  Polyurethane tiles]
Message-ID: <mailman.628.1241788155.7676.atm@atmlist.net>

  I Jb weld my tiles to an oven baked plaster mold with no problems...im sure there are many ways to skin the tool cat. 
-----Original Message-----
Date: Friday, May 08, 2009 7:36:31 am
To: "ATM List" <atm at atmlist.net>
From: "Michael Coslo" <mjc5 at psu.edu>
Subject: Re: [ATM] [Fwd: Re:  Polyurethane tiles]


On May 7, 2009, at 9:30 PM, Mark Holm wrote:

> I haven't tried it, but one point to keep in mind is that Gorilla  
> Glue foams as it cures, expanding.  Could give unexpected results.


	Gorilla glue might not be the best choice - it's also hydrophilic.  
But I believe it will send the excess glue to the side as it cures,  
and my hydrophilic fears might be moot. Who knows, it might get  
stronger with each wet?

	But that being said Tom, I would recommend trying it, then reporting  
back to us. It just might work well.


> Why not use the tile in stone method???  works great for a lot of  
> us.  It's quick, no glue to mess with and you are good to go in an  
> hour or less.


	If I might be a little controversial here, it seems that a sort of  
"this is how it must be done" has grown around tool construction.  
Certainly I've been told about my tool construction and composition  
shortcomings.

And yet my tools have produced some fine mirrors. There is a whole  
world out there 


From mjc5 at psu.edu  Fri May  8 22:24:23 2009
From: mjc5 at psu.edu (Michael Coslo)
Date: Fri, 08 May 2009 09:24:23 -0400
Subject: [ATM] [Fwd: Re:  Polyurethane tiles]
In-Reply-To: <mailman.628.1241788155.7676.atm@atmlist.net>
References: <mailman.628.1241788155.7676.atm@atmlist.net>
Message-ID: <F1CA993C-158E-4794-8B60-405AB031BADA@psu.edu>


On May 8, 2009, at 9:09 AM, TONY B wrote:

>  I Jb weld my tiles to an oven baked plaster mold with no problems...


That's pretty strong - I can't envision those tiles *ever* coming off.


-73 de Mike N3LI -



From dlwebb at canit.se  Fri May  8 23:25:10 2009
From: dlwebb at canit.se (Dominic-Luc Webb)
Date: Fri, 8 May 2009 16:25:10 +0200 (MET DST)
Subject: [ATM] [Fwd: Re:  Polyurethane tiles]
In-Reply-To: <38489013-26FA-467D-B4B9-22E0244C8893@psu.edu>
Message-ID: <Pine.LNX.4.44.0905081558360.11993-100000@uno.canit.se>


On Fri, 8 May 2009, Michael Coslo wrote:
>
> 	Gorilla glue might not be the best choice - it's also hydrophilic.

Not sure about hydrophilic, but polyurethane's in general
require some amount of water to cure properly. Some
vendors mention it on the bottle, others do not, but I
have not so far seen one that did not cure well in the
presence of at least a little water and preferably
high humidity (> 65%). For my tiles, I sprayed water
on the tool and dipped the tile in water. Then applied
glue to wet tool and pressed the wet tile into place.
Kept it in wet sink overnight and result so far is
quite strong.

I have since used polyurethane glue with plaster for
other purposes, also with success. For instance, I
use this for plaster-plaster contact to make/repair
forms for fiberglass reinforced polyester / carbon
fiber reinforced epoxy, etc. The polyurethane to
plaster contact so far looks really strong.

Dominic


From blaktony86 at yahoo.com  Sat May  9 02:18:50 2009
From: blaktony86 at yahoo.com (TONY B)
Date: Fri, 08 May 2009 12:18:50 CDT
Subject: [ATM] [Fwd: Re:  Polyurethane tiles]
Message-ID: <mailman.638.1241803135.7676.atm@atmlist.net>

   No, oven bake, then glue with jb weld. Thats how i do it and never had a tile fall off.
-----Original Message-----
Date: Friday, May 08, 2009 11:47:25 am
To: "TONY B" <blaktony86 at yahoo.com>
From: "Dominic-Luc Webb" <dlwebb at canit.se>
Subject: Re: [ATM] [Fwd: Re:  Polyurethane tiles]

On Fri, 8 May 2009, TONY B wrote:

>   I just put it in the oven @450F for 2 hrs. It bakes out the excess moisture so the tile adheres better with whatever you use to glue it to.

So, if I understood, you are gluing before oven?

Dominic




From AMaroney at sptimes.com  Sat May  9 02:58:57 2009
From: AMaroney at sptimes.com (AMaroney at sptimes.com)
Date: Fri, 8 May 2009 13:58:57 -0400
Subject: [ATM] [Fwd: Re:  Polyurethane tiles]
In-Reply-To: <4A038B44.6040401@gmail.com>
Message-ID: <OF049E45EF.A188977F-ON852575B0.00624E59-852575B0.0062C84D@sptimes.com>

> Why not use the tile in stone method??? 

Epoxy can be heated with a torch and the old tile can be removed from the 
tool.   This is good if you want to reuse the dental stone or hydrostone, 
especially in a class.

Allen Maroney
http://www.telescopelab.com


From tstokes at pacbell.net  Sat May  9 03:08:55 2009
From: tstokes at pacbell.net (Tom Stokes)
Date: Fri, 8 May 2009 11:08:55 -0700
Subject: [ATM] [Fwd: Re:  Polyurethane tiles]
References: <4A038B44.6040401@gmail.com>
Message-ID: <C248E9F6FACC4A7188C1437A70885CE1@tom>

//--------- note - I sent this to Mark ----- meant to send to the 
list ----//

Mark, I'm aware of the tile in stone method, but there are a few things
worth considering.

I do use 1" square tiles but are the channels going to stay open enough?

I have a few spent tools in my garage that have four layers of tile. How do
you tell when your tiles are too thin? I would hate to run out of tile at
#400 grit. Especially bad if doing lenses.

I can get a caulking gun size of polyurethane for about $5. I've used the
stuff on plywood and it's pretty good. Glue expansion could be a problem and
can't be overlooked. I figured a dab on the back side each tile just might
work. Just don't wet it.

Lastly, I want to try it (maybe).

Tom Stokes


----- Original Message ----- 
From: "Mark Holm" <holmmarkd at gmail.com>
To: "ATM List" <atm at atmlist.net>
Sent: Thursday, May 07, 2009 6:30 PM
Subject: [ATM] [Fwd: Re: Polyurethane tiles]


>
>
>
> I haven't tried it, but one point to keep in mind is that Gorilla Glue 
> foams as it cures, expanding.  Could give unexpected results.
>
> Why not use the tile in stone method???  works great for a lot of us. 
> It's quick, no glue to mess with and you are good to go in an hour or 
> less.
>
> see it here  http://gotgrit.com/make_tool1.php
>
> Tom Stokes wrote:
>> Has anyone made a tile tool of Hydrostone/dental stone using polyurethane 
>> glue (e.g. Gorilla glue) to bond the tiles?
>>
>> Tom Stokes
>> http://www.mirrorgrindingmachine.com/
>>
>> _______________________________________________
>> ATM mailing list http://www.atmlist.net/
>
>
> -- 
> Mark Holm
> markholm at verizon.net
> holmmarkd at gmail.com
>
>
> _______________________________________________
> ATM mailing list http://www.atmlist.net/ 


From mjc5 at psu.edu  Sat May  9 03:59:18 2009
From: mjc5 at psu.edu (Michael Coslo)
Date: Fri, 08 May 2009 14:59:18 -0400
Subject: [ATM] [Fwd: Re:  Polyurethane tiles]
In-Reply-To: <C248E9F6FACC4A7188C1437A70885CE1@tom>
References: <4A038B44.6040401@gmail.com> <C248E9F6FACC4A7188C1437A70885CE1@tom>
Message-ID: <DA1A8CCD-569F-461D-92B5-C9680ACD09D9@psu.edu>


On May 8, 2009, at 2:08 PM, Tom Stokes wrote:



> I do use 1" square tiles but are the channels going to stay open  
> enough?
>
> I have a few spent tools in my garage that have four layers of tile.  
> How do
> you tell when your tiles are too thin? I would hate to run out of  
> tile at
> #400 grit. Especially bad if doing lenses.


Are you using porcelain tiles? they should last as long as the glass  
does.

I don't set my tiles in cement, I use 1 inch tiles glued onto  the  
tool. so my channels are whatever the height of the tile is.



-73 de Mike N3LI -



From rmay at nethere.com  Sat May  9 05:18:49 2009
From: rmay at nethere.com (Bob May)
Date: Fri, 8 May 2009 13:18:49 -0700
Subject: [ATM] Lightweight glass
References: <4A030122.2010208@isp.com>
	<4085BCA3B9BF4EEBB178C764942ABC07@piv555a133b59e>
	<002e01c9cf51$57f144e0$8f78fea9@amd>
	<C2CEBED8-3B63-4BAA-BDF7-245932588002@ct-astronomer.com>
Message-ID: <000401c9d01a$3385bea0$8f78fea9@amd>

RTMC is just right up the hill for me, about 2 1/2 hours away.
Unfortunately, Stellafane is now out of range as I have vision
problems that preclude my driving very much and not at all at
night.  Just got my blank yesterday and the box is LIGHT!
Haven't opened it yet but I will tomorrow.
Bob May

rmay at nethere.com
http: slash /nav.to slash bobmay
http: slash /bobmay dot astronomy.net



From rmay at nethere.com  Sat May  9 05:25:03 2009
From: rmay at nethere.com (Bob May)
Date: Fri, 8 May 2009 13:25:03 -0700
Subject: [ATM] Lightweight glass
References: <4A030122.2010208@isp.com>	<4085BCA3B9BF4EEBB178C764942ABC07@piv555a133b59e>
	<002e01c9cf51$57f144e0$8f78fea9@amd> <4A044008.7060800@isp.com>
Message-ID: <000701c9d01b$1223cbc0$8f78fea9@amd>

Bubbling up a piece of glass won't be all that easy to do.
HexTek mirrors were thin tubes of significant size that fused
together at the ends and together in between.  Those blanks were
of significant size and of a very light weight.  I've worked with
several of Richard Schwartz's mirrors and they are lighter than a
solid glass but they are still fairly heavy as he's using thick
glass for the ribs which are fairly closely spaced.  Somebody
else has used posts to isolate the two surfaces buy I haven't
seen one much less played with it so I don't know how well it
works but he's apparently built several mirrors that way.
Blowing bubbles into glass will be a fun trip tho.
Bob May

rmay at nethere.com
http: slash /nav.to slash bobmay
http: slash /bobmay dot astronomy.net



From rmay at nethere.com  Sat May  9 05:30:14 2009
From: rmay at nethere.com (Bob May)
Date: Fri, 8 May 2009 13:30:14 -0700
Subject: [ATM] Polyurethane tiles
References: <92AA4ACBDFB2407AB6433852EC62F19E@tom>
Message-ID: <001201c9d01b$cb9b0b40$8f78fea9@amd>

The first falicy is needing to use any glue to put the tiles to
the hydrostone or other material.  The tiles should be put into
the hydrostone and if there is anything you really feel the need
to do is to put a few grooves in the edge of the tile (at least
1/2 way down)  to let them be captured better by the poured
stone.   Personally I've never had a tile come loose unless it
was a partial tile and  came out sideways at the edge.  So far,
I've used several hundred pounds of poured stone on tools, even
recycling some in large tools.
Bob May

rmay at nethere.com
http: slash /nav.to slash bobmay
http: slash /bobmay dot astronomy.net



From rmay at nethere.com  Sat May  9 05:34:42 2009
From: rmay at nethere.com (Bob May)
Date: Fri, 8 May 2009 13:34:42 -0700
Subject: [ATM] [Fwd: Re:  Polyurethane tiles]
References: <mailman.638.1241803135.7676.atm@atmlist.net>
Message-ID: <002301c9d01c$6b6df600$8f78fea9@amd>

Note that epoxies go off faster when they are heated.  Put a tile
on a hot tool and before you get the job done, most of them will
be fixed solid.  Helps in getting thing glued fast but you then
end up with a very rough surface that needs a bit of grinding to
get the tiles all at the same level.
Bob May

rmay at nethere.com
http: slash /nav.to slash bobmay
http: slash /bobmay dot astronomy.net



From tstokes at pacbell.net  Sat May  9 06:04:02 2009
From: tstokes at pacbell.net (Tom Stokes)
Date: Fri, 8 May 2009 14:04:02 -0700
Subject: [ATM] [Fwd: Re:  Polyurethane tiles]
References: <4A038B44.6040401@gmail.com> <C248E9F6FACC4A7188C1437A70885CE1@tom>
	<DA1A8CCD-569F-461D-92B5-C9680ACD09D9@psu.edu>
Message-ID: <B7205FD67ECD4599947682DC15FC81D8@tom>

> Are you using porcelain tiles? they should last as long as the glass
> does.

I should have mentioned that I am using a machine. There are some of us in
the M-o-M group http://tech.groups.yahoo.com/group/Mirror-O-Matic/ that are
resorting to standing the tiles vertically.

Tom Stokes
http://www.mirrorgrindingmachine.com/

----- Original Message ----- 
From: "Michael Coslo" <mjc5 at psu.edu>
To: "ATM List" <atm at atmlist.net>
Sent: Friday, May 08, 2009 11:59 AM
Subject: Re: [ATM] [Fwd: Re: Polyurethane tiles]


>
> On May 8, 2009, at 2:08 PM, Tom Stokes wrote:
>
>
>
>> I do use 1" square tiles but are the channels going to stay open  enough?
>>
>> I have a few spent tools in my garage that have four layers of tile.  How
>> do
>> you tell when your tiles are too thin? I would hate to run out of  tile
>> at
>> #400 grit. Especially bad if doing lenses.
>
>
> Are you using porcelain tiles? they should last as long as the glass
> does.
>
> I don't set my tiles in cement, I use 1 inch tiles glued onto  the  tool.
> so my channels are whatever the height of the tile is.
>
>
>
> -73 de Mike N3LI -
>
>
> _______________________________________________
> ATM mailing list http://www.atmlist.net/


From holmmarkd at gmail.com  Sat May  9 09:39:28 2009
From: holmmarkd at gmail.com (Mark Holm)
Date: Fri, 08 May 2009 20:39:28 -0400
Subject: [ATM] [Fwd: Re:  Polyurethane tiles]
In-Reply-To: <38489013-26FA-467D-B4B9-22E0244C8893@psu.edu>
References: <4A038B44.6040401@gmail.com>
	<38489013-26FA-467D-B4B9-22E0244C8893@psu.edu>
Message-ID: <4A04D0C0.1080504@gmail.com>

If I might defend myself a bit:

The tile-in-stone method is not very old, perhaps around a decade. (I 
certainly did not invent it.)

In fact, the glue-tile-on-plaster method is older, by a decade or two.  
I distinctly remember an article about it in S&T in the late 80's.  It 
was touted then, as a revolutionary replacement for solid glass tools.   
When I recommend the tile-in-stone method, I am actually being 
avant-garde compared to the dinosaurs who recommend epoxying tile to 
tools  ;)

There are a bunch of ways to make tools that work.  The main reason I 
push the tile-in-stone method is that it is so easy, quick, and so well 
adapted for the "vanilla" mirror making project.  I just can't figure 
why, excepting some special demands of a particular project, you want to 
wait days for plaster, or anything else, to dry so you can have the 
tedious fun of mixing up epoxy (not to mention the very real epoxy 
allergy thing), and gluing on tiles.  Do the whole job at once, and be 
grinding the same evening.

In my view, tile-in-stone should be the default method we recommend to 
beginners in North America, Europe, Australia and perhaps most other 
urbanized areas.  This is just like saying that one should try to get 
optical grade pitch and polishing compounds.  It's not that other things 
will not work, but that this is the easiest, quickest way short of 
getting a solid glass tool.  Note that nobody recommends solid glass 
tools anymore despite the fact that they are far and away the easiest to 
get going with.  If I really wanted to be old fashioned and stubborn, I 
would demand solid glass.

There are really only two material demands for tile-in-stone tools.
1. Dental stone, or a product like Hydrostone.
2. Suitable tiles in the mat form.

Since dentistry is one of the first bits of industrialized culture to 
permeate even third world areas, the probability of being able to find 
dental stone is actually pretty high.  Hydrostone and similar products 
are widely used in building products, so where reasonably modern 
buildings are going up, Hydrostone like materials are reasonably likely 
to be available too.

The tile requirements for glued and tile-in-stone tools are exactly the 
same, except for the requirement that tile-in-stone tiles need to be 
held together with a mesh on the back.  This is now a common technology 
for tile laying and tile laying is hardly the exclusive province of 
highly industrialized societies.  In fact, I can easily imagine using 
some glue and string to make my own tile mat.  Wouldn't be any harder 
than gluing tile to plaster.

I don't see why anybody thinks it will be easier or cheaper to find 
epoxy glue in out of the way places than dental plaster.  I think the 
main reason epoxy remains so popular in the USA is that Home Despot 
stocks it.  (That's not entirely a bad reason.  Ease of acquisition is 
part of the equation.)

-- 
Mark Holm
markholm at verizon.net
holmmarkd at gmail.com


Michael Coslo wrote:
>
>
>     If I might be a little controversial here, it seems that a sort of 
> "this is how it must be done" has grown around tool construction. 
> Certainly I've been told about my tool construction and composition 
> shortcomings.
>
> And yet my tools have produced some fine mirrors. There is a whole 
> world out there beyond dental stone.
>


From gfbrandenburg at yahoo.com  Sat May  9 21:24:07 2009
From: gfbrandenburg at yahoo.com (Guy Brandenburg)
Date: Sat, 9 May 2009 05:24:07 -0700 (PDT)
Subject: [ATM] Lightweight glass
Message-ID: <94355.14466.qm@web111509.mail.gq1.yahoo.com>


Bob,
How was the richard schwartz sandwich glass to use and figure?

Guy Brandenburg,

--- On Fri, 5/8/09, Bob May <rmay at nethere.com> wrote:

> From: Bob May <rmay at nethere.com>
> Subject: Re: [ATM] Lightweight glass
> To: atm at atmlist.net
> Date: Friday, May 8, 2009, 4:25 PM
> Bubbling up a piece of glass won't be
> all that easy to do.
> HexTek mirrors were thin tubes of significant size that
> fused
> together at the ends and together in between.? Those
> blanks were
> of significant size and of a very light weight.? I've
> worked with
> several of Richard Schwartz's mirrors and they are lighter
> than a
> solid glass but they are still fairly heavy as he's using
> thick
> glass for the ribs which are fairly closely spaced.?
> Somebody
> else has used posts to isolate the two surfaces buy I
> haven't
> seen one much less played with it so I don't know how well
> it
> works but he's apparently built several mirrors that way.
> Blowing bubbles into glass will be a fun trip tho.
> Bob May
> 
> rmay at nethere.com
> http: slash /nav.to slash bobmay
> http: slash /bobmay dot astronomy.net
> 
> 
> _______________________________________________
> ATM mailing list http://www.atmlist.net/
> 


      

From f.franssen at planet.nl  Sat May  9 23:19:01 2009
From: f.franssen at planet.nl (Frans Franssen)
Date: Sat, 9 May 2009 16:19:01 +0200
Subject: [ATM] Bryan Greer
Message-ID: <CPSMTPM-EML110edC8m0001768a@CPSMTPM-EML110.kpnxchange.com>

Hello to all,
 
Does anybody out there know the whereabouts of Bryan Greer, the one who has
published several articles in S & T about air currents in telescopes. He
doesn't react to my e-mails. Thank you for any info. F. Franssen.

From blaktony86 at yahoo.com  Sat May  9 23:21:29 2009
From: blaktony86 at yahoo.com (TONY B)
Date: Sat, 09 May 2009 09:21:29 CDT
Subject: [ATM] Diamond hone for beveling
Message-ID: <mailman.680.1241878893.7676.atm@atmlist.net>

Well i found the diamond hone set at harbor freight. I will now attempt to bevel. Wish me luck!! 


From holmmarkd at gmail.com  Sat May  9 23:40:03 2009
From: holmmarkd at gmail.com (Mark Holm)
Date: Sat, 09 May 2009 10:40:03 -0400
Subject: [ATM] Bryan Greer
In-Reply-To: <CPSMTPM-EML110edC8m0001768a@CPSMTPM-EML110.kpnxchange.com>
References: <CPSMTPM-EML110edC8m0001768a@CPSMTPM-EML110.kpnxchange.com>
Message-ID: <4A0595C3.9090504@gmail.com>

Bryan used to work at FPI-Protostar.  I don't know if he still does.  
You could try there.   protostar at fpi-protostar.com 
<mailto:protostar at fpi-protostar.com>

Frans Franssen wrote:
> Hello to all,
>  
> Does anybody out there know the whereabouts of Bryan Greer, the one who has
> published several articles in S & T about air currents in telescopes. He
> doesn't react to my e-mails. Thank you for any info. F. Franssen.
> _______________________________________________
> ATM mailing list http://www.atmlist.net/
>   


-- 
Mark Holm
markholm at verizon.net
holmmarkd at gmail.com


From blaktony86 at yahoo.com  Sun May 10 02:09:09 2009
From: blaktony86 at yahoo.com (TONY BLAKESLEY)
Date: Sat, 9 May 2009 10:09:09 -0700 (PDT)
Subject: [ATM] Diamond hone for beveling
In-Reply-To: <mailman.680.1241878893.7676.atm@atmlist.net>
Message-ID: <64603.30505.qm@web81905.mail.mud.yahoo.com>

WOW,
?
I must say this is the best procedure for beveling. I completely beveled front and back side of my 9.2" mirror in about an hour. There were no flakes or scallops produced from the bevel. I beveled the mirror using the diamond hone @ a 45 degree angle and applied pressure only to the downward strokes. It really is like cutting butter. No grit either to scratch mirror. I had a completely polished surface and didnt find one scratch. I did have my mirror wet the entire time by squirting water while grinding the bevel.
?
Thanks guys for the tip! Now I can go ahead and hopefully polish the surface without it sticking. 
?
Oh yeah I forgot to mention, The little pit/chip was actually a white impurity in the mirror. It wasnt a bubble but I got past it and hopefully I can polish/figure the mirror without it catching. I think it messed up the figure around this little impurity, but hopefully it can be easily worked out since it was such a tiny object (less than 1/8" long).
?
-Tony

--- On Sat, 5/9/09, TONY B <blaktony86 at yahoo.com> wrote:

From: TONY B <blaktony86 at yahoo.com>
Subject: [ATM] Diamond hone for beveling
To: atm at atmlist.net
Date: Saturday, May 9, 2009, 9:21 AM

Well i found the diamond hone set at harbor freight. I will now attempt to
bevel. Wish me luck!! 

_______________________________________________
ATM mailing list http://www.atmlist.net/

From mirceapte at yahoo.com  Sun May 10 04:03:19 2009
From: mirceapte at yahoo.com (Mircea Pteancu)
Date: Sat, 9 May 2009 12:03:19 -0700 (PDT)
Subject: [ATM] Duplov apochromat
Message-ID: <97935.27579.qm@web35807.mail.mud.yahoo.com>

Hello
I have only mirrors,the most ''complex'' lense I own?is a 60mm dublet?of 310mm f'.l.
I joined this list one and half years ago and I?don't remember? references to such apochromats using normal,or only slightly exotic?optical glasses.Maybe some of you will find this article? as interesting.It was?brought to my attention by zoth,a colleague moderator on our Romanian forum ''astronomy.ro''.?
http://bossanova9.org/astro/optics/normal%20glass%20apo%20-%20duplov.pdf
?
Regards,Mircea


      

From tstokes at pacbell.net  Sun May 10 06:42:22 2009
From: tstokes at pacbell.net (Tom Stokes)
Date: Sat, 9 May 2009 14:42:22 -0700
Subject: [ATM] [Fwd: Re:  Polyurethane tiles]
References: <4A038B44.6040401@gmail.com><38489013-26FA-467D-B4B9-22E0244C8893@psu.edu>
	<4A04D0C0.1080504@gmail.com>
Message-ID: <C14EBA31D1AD43A199AF6E55BCE2611A@tom>

For what it is worth, this is a picture of a tile-in-plaster tool I made
circa '69 or '70 for a 5" Mak corrector.

http://www.mirrorgrindingmachine.com/transient/DSCN0070.JPG

I used to have the matching concave tool but I ground through the tiles
during fine grinding and threw it away. Chickened out and went on to another
project.

I do vaguely remember that I cast the plaster base against the molded blank,
epoxied on the tiles, and filled the channels with plaster.

Tom Stokes

----- Original Message ----- 
From: "Mark Holm" <holmmarkd at gmail.com>
To: "Michael Coslo" <mjc5 at psu.edu>
Cc: "ATM List" <atm at atmlist.net>
Sent: Friday, May 08, 2009 5:39 PM
Subject: Re: [ATM] [Fwd: Re: Polyurethane tiles]


>
> The tile-in-stone method is not very old, perhaps around a decade. (I
> certainly did not invent it.)
>
> In fact, the glue-tile-on-plaster method is older, by a decade or two.  I
> distinctly remember an article about it in S&T in the late 80's.  It was
> touted then, as a revolutionary replacement for solid glass tools.   When
> I recommend the tile-in-stone method, I am actually being avant-garde
> compared to the dinosaurs who recommend epoxying tile to tools  ;)



From rmay at nethere.com  Sun May 10 08:10:07 2009
From: rmay at nethere.com (Bob May)
Date: Sat, 9 May 2009 16:10:07 -0700
Subject: [ATM] Lightweight glass
References: <94355.14466.qm@web111509.mail.gq1.yahoo.com>
Message-ID: <000601c9d0fb$4c30b900$8f78fea9@amd>

Guy, Richard's glass was pretty easy to grind.  It's problem is
that it is somewhat sensitive to temps so you can't just throw
some pitch on it or it will then crack.  Richard did several
samples and I found him up at RTMC ahd discussed the problems he
had and told him that I could polish out the last one he had.
Technique on putting the pitch was to put everything under water
and heat it up on the stove (no wife, no problem!)  Used a mold
that I made (silicone rubber with holes punched in it which made
for buttons of pitch to the glass surface.  Letting things cool
after the pitch mostly made it to the glass and I had a pitch lap
which I then used to polish the glass out.  Put a nice surface on
it and took it up to RTMC the next year, showed it around and
found Richard and passed it on to him.  From what I have heard
from him is that his wife now has that mirror in a telescope
(ref. the paint incompaibilities he had a while ago with
polyurethane paint that didn't dry from the stain he used).
It was a nice interesting project!
See the post on David Davis's mirror for more fun.
Bob May

rmay at nethere.com
http: slash /nav.to slash bobmay
http: slash /bobmay dot astronomy.net



From rmay at nethere.com  Sun May 10 08:14:45 2009
From: rmay at nethere.com (Bob May)
Date: Sat, 9 May 2009 16:14:45 -0700
Subject: [ATM] [Fwd: Re:  Polyurethane tiles]
References: <4A038B44.6040401@gmail.com>
	<C248E9F6FACC4A7188C1437A70885CE1@tom><DA1A8CCD-569F-461D-92B5-C9680ACD09D9@psu.edu>
	<B7205FD67ECD4599947682DC15FC81D8@tom>
Message-ID: <000f01c9d0fb$f1c8b0c0$8f78fea9@amd>

IF YOU USE THE TILE TOOL TO DO THE INITIAL CARVING, YOU WILL FIND
IT BETTER TO DO THE TILES ON EDGE!!!   Do the initial hole
carving (generating the curve) with iron tools or diamond tools
and there will be a lot less need for the thickness of the tiles.
If you do a good job of getting a spherical surface according to
a spherometer (within a thousandths or three) over the surface,
you should be able to do 3 or 4 mirrors with the same tool
without any worry.
Bob May

rmay at nethere.com
http: slash /nav.to slash bobmay
http: slash /bobmay dot astronomy.net



From rmay at nethere.com  Sun May 10 08:34:47 2009
From: rmay at nethere.com (Bob May)
Date: Sat, 9 May 2009 16:34:47 -0700
Subject: [ATM] Diamond hone for beveling
References: <64603.30505.qm@web81905.mail.mud.yahoo.com>
Message-ID: <002001c9d0fe$be077480$8f78fea9@amd>

An inclusin in the glass will make for fun as it is probably
going to be harder than the glass itself.  You did the right
thing by grinding it out of the glass.
Bob May

rmay at nethere.com
http: slash /nav.to slash bobmay
http: slash /bobmay dot astronomy.net



From rmay at nethere.com  Sun May 10 09:00:29 2009
From: rmay at nethere.com (Bob May)
Date: Sat, 9 May 2009 17:00:29 -0700
Subject: [ATM] David Davis lightweight blank I got.
Message-ID: <003401c9d102$55375840$8f78fea9@amd>

Opened the box from David and found a very lightweight 8" blank
of his attempt at an ultralightweight blank.
First was to measure to find what kind of ROC I got.  It is about
21" FL so it is going to be some fun!  The front surface appears
to be single thickness glass (regular window glass!) backed up by
a glass foam so that the whole thing appears to be about a full
thickness blank.  The front surface appears to be glued to the
foam with gorilla glue or something like that.
The front surface wasn't a good sphere so I had to spend some
time making it spherical but it was interesting to watch the hole
in the middle disappear along with the TDE.  At this point, I've
gotten 120 grit done.  Next week is going down through the grits.
Week after that is RTMC so I'll be up there on Sat. and will have
the blank available for viewing.
The blank is so light that I let it float in the wash water and
it only went in about 1/4" or less!!!
Bob May

rmay at nethere.com
http: slash /nav.to slash bobmay
http: slash /bobmay dot astronomy.net



From rmay at nethere.com  Sun May 10 09:18:31 2009
From: rmay at nethere.com (Bob May)
Date: Sat, 9 May 2009 17:18:31 -0700
Subject: [ATM] Duplov apochromat
References: <97935.27579.qm@web35807.mail.mud.yahoo.com>
Message-ID: <003501c9d104$d9f5aa80$8f78fea9@amd>

The problem with optical glasses (glass in general actually) is
that the dispersion curves are just that, curves, and as a
result, it is difficult to get two curves that match their slopes
so that the light is properly refracted to the same spot.  The
errors aren't large but they are there.  The exitic glasses do
have their curves different from "normal" glasses (the normal
glasses are glasses that conform to a curve in the Nd/Vd chart)
in that the dispersion is different from what the normal line of
glasses is.  This makes it possible to better match the amount of
dispersion of the light to another glass over the spectrum of
light.  Needless to say, the obtaining of an exact match between
the dispersions of the various glasses is an almost impossible
task.
What makes things easier tho is to use more glasses which can
then compensate better for color errors.  Using 5 or more glass
pieces improves this a lot over the 2 glass doublets.  The
article shows 3 sets of glasses to obtain a high quality of
compliance of the dispersion of the light.  Unfortunately, what
happens is that each surface of the glass (uncoated glass)
reflects about 4% of the light so having 10 surfaces will mean a
large loss of light.  For planetary viewing, that isn't so bad
but still losing almost a magnitude of light is a big loss for a
star viewing telescope, not so bad with a planetary telescope.
I'll note that you do want to do large magnifications when
looking at planets so that means that a design of a larger
(150-250mm) aperture and a longer FL.  The larger aperture makes
matching glass harder but the longer FL makes it easier and I
will comment here that focal lengths on the order of 5 meters
will make for an excellent telescope for planetary viewing as the
image scale (how big things are at the focal plane of the
telescope) is larger which means that you can use larger EPs that
have better control of the aberrations that happen in the EP.
Good luck!
Bob May

rmay at nethere.com
http: slash /nav.to slash bobmay
http: slash /bobmay dot astronomy.net



From blaktony86 at yahoo.com  Sun May 10 09:58:25 2009
From: blaktony86 at yahoo.com (TONY B)
Date: Sat, 09 May 2009 19:58:25 CDT
Subject: [ATM] David Davis lightweight blank I got.
Message-ID: <mailman.702.1241917109.7676.atm@atmlist.net>

 Id like to see a picture of that!
-----Original Message-----
Date: Saturday, May 09, 2009 6:57:52 pm
To: <atm at atmlist.net>
From: "Bob May" <rmay at nethere.com>
Subject: [ATM] David Davis lightweight blank I got.

Opened the box from David and found a very lightweight 8" blank
of his attempt at an ultralightweight blank.
First was to measure to find what kind of ROC I got.  It is about
21" FL so it is going to be some fun!  The front surface appears
to be single thickness glass (regular window glass!) backed up by
a glass foam so that the whole thing appears to be about a full
thickness blank.  The front surface appears to be glued to the
foam with gorilla glue or something like that.
The front surface wasn't a good sphere so I had to spend some
time making it spherical but it was interesting to watch the hole
in the middle disappear along with the TDE.  At this point, I've
gotten 120 grit done.  Next week is going down through the grits.
Week after that is RTMC so I'll be up there on Sat. and will have
the blank available for viewing.
The blank is so light that I let it float in the wash water and
it only went in about 1/4" or less!!!
Bob May

rmay at nethere.com
http: slash /nav.to slash bobmay
ht


From vladimir.galogaza1 at zg.t-com.hr  Sun May 10 16:45:40 2009
From: vladimir.galogaza1 at zg.t-com.hr (Vladimir Galogaza)
Date: Sun, 10 May 2009 09:45:40 +0200
Subject: [ATM] David Davis lightweight blank I got.
References: <003401c9d102$55375840$8f78fea9@amd>
Message-ID: <3D6D1A3FBB7A495BA68A169423D46E95@piv555a133b59e>

Bob and David,

I am very interested in having this 8" foam backed 21" FL mirror
for testing with PSI-Bath interferometer.

Would it be possible to get it after you are finished with RTMC and
possibly some other projects in the future.

I can use it weather spherical or paraboloidal or anything in between
(or outside).

If  you will consider it would it be possible to have it coated before 
sending to me.

Regards
Vladimir. 


From camkit at mweb.co.za  Sun May 10 18:35:27 2009
From: camkit at mweb.co.za (chris forder)
Date: Sun, 10 May 2009 11:35:27 +0200
Subject: [ATM] [Fwd: Re:  Polyurethane tiles]
Message-ID: <4A069FDF.1070406@mweb.co.za>

My personal choice is to epoxy the tiles to a cement tool. The channels 
are there and you can see how nuch tile thickness remains.
I always rough out the sag on the mirror with a large angle grinder. 
That way less tool is used in your mirror making. My tiles are made of 
floor tiles and last for about three or four mirrors of the same size & sag.

Chris Cape Town

From jbentz at inreach.com  Mon May 11 02:06:35 2009
From: jbentz at inreach.com (Jan Bentz)
Date: Sun, 10 May 2009 10:06:35 -0700
Subject: [ATM] Duplov apochromat
In-Reply-To: <97935.27579.qm@web35807.mail.mud.yahoo.com>
References: <97935.27579.qm@web35807.mail.mud.yahoo.com>
Message-ID: <4A07099B.2070900@inreach.com>

Mircea Pteancu wrote:

>Hello
>I have only mirrors,the most ''complex'' lense I own is a 60mm dublet of 310mm f'.l.
>I joined this list one and half years ago and I don't remember  references to such apochromats using normal,or only slightly exotic optical glasses.Maybe some of you will find this article  as interesting.It was brought to my attention by zoth,a colleague moderator on our Romanian forum ''astronomy.ro''. 
>http://bossanova9.org/astro/optics/normal%20glass%20apo%20-%20duplov.pdf
> 
>Regards,Mircea
>
>
>      
>_______________________________________________
>ATM mailing list http://www.atmlist.net/
>
>  
>
Mircea -- I raytraced all three of the systems described and they all 
appeared to do what is claimed in the paper.  Some problems were left 
out of the description however.  Aside from the obvious construction 
problems these systems all have a fairly small field of high quality and 
are all 1.5 to 2.5 times longer than their focal length.  The curvature 
of field ranges from about -150 to -200mm but is largely compensated for 
by alot of astigmatism.  I have not done a tolerance analysis but the 
concentricity would be very critical because of the widely separated 
components.  Some of the elements are cemented so the loss of light 
would not be quite so high as Bob May implied.   The usual trouble with 
widely separated component systems where each component is not 
seperately achromatised  is the large chromatic differance of 
magnification (lateral color) but  these designs ingeniously correct for 
that.  They would certainly be suitable for a planetary scope if 
properly constructed - a big if.

Jan Bentz

From richard at foucault.co.uk  Mon May 11 03:03:26 2009
From: richard at foucault.co.uk (Richard in the UK)
Date: Sun, 10 May 2009 19:03:26 +0100
Subject: [ATM] Duplov apochromat
In-Reply-To: <4A07099B.2070900@inreach.com>
References: <97935.27579.qm@web35807.mail.mud.yahoo.com>
	<4A07099B.2070900@inreach.com>
Message-ID: <1983857769.20090510190326@foucault.co.uk>

Hello Jan,

Sunday, May 10, 2009, 6:06:35 PM, you wrote:

> these systems all have a fairly small field of high quality


I would call it a very limited field. The errors of the 90mm f/7 start
increasing very quickly once the field is more than 5mm diameter. Do a
direct comparison of the 90mm f/7 with a 90mm f/7 Newtonian and, over
the very limited field that this "apo" has, you will see little
difference. In fact, paraxially, the newt outperforms it. For 14
optical surfaces, I would have expected more.

-- 
Best regards,
 Richard in the UK


From rmay at nethere.com  Mon May 11 06:33:51 2009
From: rmay at nethere.com (Bob May)
Date: Sun, 10 May 2009 14:33:51 -0700
Subject: [ATM] [Fwd: Re:  Polyurethane tiles]
References: <4A069FDF.1070406@mweb.co.za>
Message-ID: <000601c9d1b7$03edb460$8f78fea9@amd>

One thing that I'm having trouble understanding is why there
needs to be channels on the tool???  Before the tile tool
evolution, nobody did channels in the second piece of glass that
was used as the tool!  Even the channeling that Newport does with
their tool blanks is a fairly new thing.  Can anybody enlighten
me as to why this has started?  I don't believe that the grit
resovoir thing is valid as the grit all falls to the bottom of
the channel and fails to then get to the grinding surface.
Bob May

rmay at nethere.com
http: slash /nav.to slash bobmay
http: slash /bobmay dot astronomy.net



From hermit at outofoptions.org  Mon May 11 07:01:05 2009
From: hermit at outofoptions.org (hermit)
Date: Sun, 10 May 2009 18:01:05 -0400
Subject: [ATM] [Fwd: Re:  Polyurethane tiles]
In-Reply-To: <000601c9d1b7$03edb460$8f78fea9@amd>
References: <4A069FDF.1070406@mweb.co.za> <000601c9d1b7$03edb460$8f78fea9@amd>
Message-ID: <4A074EA1.1000603@outofoptions.org>

Bob May wrote:
> One thing that I'm having trouble understanding is why there
> needs to be channels on the tool???  Before the tile tool
> evolution, nobody did channels in the second piece of glass that
> was used as the tool!  Even the channeling that Newport does with
> their tool blanks is a fairly new thing.  Can anybody enlighten
> me as to why this has started?  I don't believe that the grit
> resovoir thing is valid as the grit all falls to the bottom of
> the channel and fails to then get to the grinding surface.
> Bob May
>
>   
Less sticking and easier to remove.  If you watch through the back of 
the glass, you will see that the grit doesn't all fall the way you might 
think.  Plus tiles come in little squares that are easy to work with. ;)

Ken Lowther

From b-hamburger at ya.com  Mon May 11 07:10:36 2009
From: b-hamburger at ya.com (Berthold Hamburger)
Date: Mon, 11 May 2009 00:10:36 +0200
Subject: [ATM] [Fwd: Re:  Polyurethane tiles]
In-Reply-To: <000601c9d1b7$03edb460$8f78fea9@amd>
References: <4A069FDF.1070406@mweb.co.za> <000601c9d1b7$03edb460$8f78fea9@amd>
Message-ID: <000401c9d1bc$267309e0$73591da0$@com>

By intuition, I would say that the channels create many individual grinding
edges that all do their job of biting into the glass. Especially since all
edges are automatically coated with grit when grinding TOT. When grinding
MOT I would suspect that grit is washed to the top of the tool by turbulence
due to the motion of liquid/water through the channels.
An analogy would be trying to cut through a piece of wood with a knife
(unchanneled tool) and then try the same thing with a serrated blade
(channeled tool). The latter will do the job faster without doubt.

Berthold

-- 
Berthold Hamburger - Cellist/Spain
Email: behambu at artinso.com
http://www.artinso.com
http://www.astro.artinso.com

> -----Original Message-----
> From: atm-bounces at atmlist.net [mailto:atm-bounces at atmlist.net] On Behalf
> Of Bob May
> Sent: domingo, 10 de mayo de 2009 23:34
> To: atm at atmlist.net
> Subject: Re: [ATM] [Fwd: Re: Polyurethane tiles]
> 
> One thing that I'm having trouble understanding is why there
> needs to be channels on the tool???  Before the tile tool
> evolution, nobody did channels in the second piece of glass that
> was used as the tool!  Even the channeling that Newport does with
> their tool blanks is a fairly new thing.  Can anybody enlighten
> me as to why this has started?  I don't believe that the grit
> resovoir thing is valid as the grit all falls to the bottom of
> the channel and fails to then get to the grinding surface.
> Bob May
> 
> rmay at nethere.com
> http: slash /nav.to slash bobmay
> http: slash /bobmay dot astronomy.net
> 
> 
> _______________________________________________
> ATM mailing list http://www.atmlist.net/


From tstokes at pacbell.net  Mon May 11 08:23:32 2009
From: tstokes at pacbell.net (Tom Stokes)
Date: Sun, 10 May 2009 16:23:32 -0700
Subject: [ATM] [Fwd: Re:  Polyurethane tiles]
References: <4A038B44.6040401@gmail.com><C248E9F6FACC4A7188C1437A70885CE1@tom><DA1A8CCD-569F-461D-92B5-C9680ACD09D9@psu.edu><B7205FD67ECD4599947682DC15FC81D8@tom>
	<000f01c9d0fb$f1c8b0c0$8f78fea9@amd>
Message-ID: <1ECC27978CBC48D6B74CA578614C175A@tom>

Bob, I'm using a MOM 20. Are you suggesting that I do this by hand or build
another machine? Granted, using abrasives on a spinning mirror does not
lead to fast hogging, but it is awfully easy to glue on another layer of
tiles and keep on trucking. We are talking an extra day or two at most. I'm
planning on making one mirror, not 3 or 4. When I do make another mirror, it
will almost certainly be a different diameter and ROC.

Tom Stokes
http://www.mirrorgrindingmachine.com/

----- Original Message ----- 
From: "Bob May" <rmay at nethere.com>
To: <atm at atmlist.net>
Sent: Saturday, May 09, 2009 4:14 PM
Subject: Re: [ATM] [Fwd: Re: Polyurethane tiles]


> IF YOU USE THE TILE TOOL TO DO THE INITIAL CARVING, YOU WILL FIND
> IT BETTER TO DO THE TILES ON EDGE!!!   Do the initial hole
> carving (generating the curve) with iron tools or diamond tools
> and there will be a lot less need for the thickness of the tiles.
> If you do a good job of getting a spherical surface according to
> a spherometer (within a thousandths or three) over the surface,
> you should be able to do 3 or 4 mirrors with the same tool
> without any worry.
> Bob May
>
> rmay at nethere.com
> http: slash /nav.to slash bobmay
> http: slash /bobmay dot astronomy.net
>
>
> _______________________________________________
> ATM mailing list http://www.atmlist.net/



From jkoptic at juno.com  Mon May 11 08:43:41 2009
From: jkoptic at juno.com (Jarvis Krumbein)
Date: Sun, 10 May 2009 16:43:41 -0700
Subject: [ATM] [Fwd: Re:  Polyurethane tiles]
Message-ID: <20090510.164341.2896.0.jkoptic@juno.com>

Bob, I always cut a few channels in my solid glass tools to prevent
sticking.  I started doing this in 1947 after a horrendus experience
working my first 12" by hand.  If you've never had a tool and mirror
suddenly firmly stuck together while in the last stage of fine grinding
you haven't lived.  It took me two weeks to get them apart and every tool
had at least one channel quickly ground in after that just to relieve the
suction.  Go back to the old ATM books to get an idea as to how much of a
problem this sometime was and for some of the novel methods of getting
two discs apart.

Jarvis Krumbein

On Sun, 10 May 2009 14:33:51 -0700 "Bob May" <rmay at nethere.com> writes:
> One thing that I'm having trouble understanding is why there
> needs to be channels on the tool???  Before the tile tool
> evolution, nobody did channels in the second piece of glass that
> was used as the tool!  Even the channeling that Newport does with
> their tool blanks is a fairly new thing.  Can anybody enlighten
> me as to why this has started?  I don't believe that the grit
> resovoir thing is valid as the grit all falls to the bottom of
> the channel and fails to then get to the grinding surface.
> Bob May
> 
> rmay at nethere.com
> http: slash /nav.to slash bobmay
> http: slash /bobmay dot astronomy.net
> 
> 
> _______________________________________________
> ATM mailing list http://www.atmlist.net/
> 

____________________________________________________________
Advance your tech career with a master's in IT!
http://thirdpartyoffers.juno.com/TGL2141/fc/BLSrjpTEgrEihBaJYdUIEbiwsSrrtsCryiXQCYaBvwZZZpurEsSqGez2EXe/

From tstokes at pacbell.net  Mon May 11 08:55:47 2009
From: tstokes at pacbell.net (Tom Stokes)
Date: Sun, 10 May 2009 16:55:47 -0700
Subject: [ATM] [Fwd: Re:  Polyurethane tiles]
References: <4A069FDF.1070406@mweb.co.za> <000601c9d1b7$03edb460$8f78fea9@amd>
Message-ID: <CD74BA23C5FA4AC78DABD64B4E743BA2@tom>

I also don't understand why Mel Bartels uses only micro faceting on his 
laps. Perhaps you "old guys" are coming up with something new.

Tom Stokes

----- Original Message ----- 
From: "Bob May" <rmay at nethere.com>
To: <atm at atmlist.net>
Sent: Sunday, May 10, 2009 2:33 PM
Subject: Re: [ATM] [Fwd: Re: Polyurethane tiles]


> One thing that I'm having trouble understanding is why there
> needs to be channels on the tool???  Before the tile tool
> evolution, nobody did channels in the second piece of glass that
> was used as the tool!  Even the channeling that Newport does with
> their tool blanks is a fairly new thing.  Can anybody enlighten
> me as to why this has started?  I don't believe that the grit
> resovoir thing is valid as the grit all falls to the bottom of
> the channel and fails to then get to the grinding surface.
> Bob May
>
> rmay at nethere.com
> http: slash /nav.to slash bobmay
> http: slash /bobmay dot astronomy.net
>
>
> _______________________________________________
> ATM mailing list http://www.atmlist.net/ 


From foreilly at verizon.net  Mon May 11 09:25:22 2009
From: foreilly at verizon.net (Francis J. O'Reilly)
Date: Sun, 10 May 2009 20:25:22 -0400
Subject: [ATM] Polyurethane tiles Shirt color
References: <20090510.164341.2896.0.jkoptic@juno.com>
Message-ID: <A1300F766A0B41759AEF1003A40916AC@HELENYLCMWAV95>

Never a dull moment when they stick.

I use channeled tools. I like the Newport tool alot. I recently used one for 
a 12.25 inch project. It worked well. I agree however that once grit gets 
into the channel, it does not come back up.

Frankly, none of this is very difficult. There are innumerable ways to make 
a mirror or a flat, most seem to work pretty well, channeled tool, 
unchanneled tool, Channeled lap or microfaceted, pregenerated curves or not, 
it doesnt really seem to matter much more than what color shirt you wear 
when working. (I prefer a Stellafane T-shirt covered by a denim apron from 
Harbor Freight)

I am somewhat amazed by the amount of discussion spent on such matters, more 
grinding and less writing about it would probably be most effective, just as 
it was in 1947.

Francis J. O'Reilly 



From hermit at outofoptions.org  Mon May 11 10:15:40 2009
From: hermit at outofoptions.org (hermit)
Date: Sun, 10 May 2009 21:15:40 -0400
Subject: [ATM] [Fwd: Re:  Polyurethane tiles]
In-Reply-To: <CD74BA23C5FA4AC78DABD64B4E743BA2@tom>
References: <4A069FDF.1070406@mweb.co.za> <000601c9d1b7$03edb460$8f78fea9@amd>
	<CD74BA23C5FA4AC78DABD64B4E743BA2@tom>
Message-ID: <4A077C3C.4020506@outofoptions.org>

Tom Stokes wrote:
> I also don't understand why Mel Bartels uses only micro faceting on 
> his laps. Perhaps you "old guys" are coming up with something new.
>
> Tom Stokes
>
I think it leads to less micro ripple if I remember correctly.  The way 
I make my laps though, I need the channels to get the mirror and lap 
into good contact.  After that, micro channels are enough to hold 
moisture and polish to prolong the 'wet'.

Ken Lowther

From brianb at myuw.net  Mon May 11 14:03:40 2009
From: brianb at myuw.net (brianb at myuw.net)
Date: Sun, 10 May 2009 22:03:40 -0700 (PDT)
Subject: [ATM] myth?
Message-ID: <Pine.LNX.4.43.0905102203400.20647@hur12.myuw.net>



All of the books say the grid pattern on a pitch lap should not be centered, as zoning will occur.
This doesn't seem right to me.
Can this really happen?



From rozer at pacbell.net  Mon May 11 15:32:47 2009
From: rozer at pacbell.net (Richard Ozer)
Date: Sun, 10 May 2009 23:32:47 -0700
Subject: [ATM] myth?
In-Reply-To: <Pine.LNX.4.43.0905102203400.20647@hur12.myuw.net>
References: <Pine.LNX.4.43.0905102203400.20647@hur12.myuw.net>
Message-ID: <4A07C68F.5010100@pacbell.net>

Yes! It's quite remarkable actually.

brianb at myuw.net wrote:
>
>
> All of the books say the grid pattern on a pitch lap should not be 
> centered, as zoning will occur.
> This doesn't seem right to me.
> Can this really happen?
>
>
> _______________________________________________
> ATM mailing list http://www.atmlist.net/
>

From dlwebb at canit.se  Mon May 11 16:57:25 2009
From: dlwebb at canit.se (Dominic-Luc Webb)
Date: Mon, 11 May 2009 09:57:25 +0200 (MET DST)
Subject: [ATM] [Fwd: Re:  Polyurethane tiles]
In-Reply-To: <DA1A8CCD-569F-461D-92B5-C9680ACD09D9@psu.edu>
Message-ID: <Pine.LNX.4.44.0905110954040.28033-100000@uno.canit.se>

On Fri, 8 May 2009, Michael Coslo wrote:
> Are you using porcelain tiles? they should last as long as the glass
> does.


I'm not so sure. My tiles behave less hard than glass and,
because they are tiles, they have less total area than the
mirror. I would expect one way or other tile thickness is
lost faster than mirror thickness.

Dominic


From dlwebb at canit.se  Mon May 11 17:02:59 2009
From: dlwebb at canit.se (Dominic-Luc Webb)
Date: Mon, 11 May 2009 10:02:59 +0200 (MET DST)
Subject: [ATM] Polyurethane tiles
In-Reply-To: <001201c9d01b$cb9b0b40$8f78fea9@amd>
Message-ID: <Pine.LNX.4.44.0905110958320.28033-100000@uno.canit.se>

On Fri, 8 May 2009, Bob May wrote:

> The first falicy is needing to use any glue to put the tiles to
> the hydrostone or other material.

Agreed. As far as I can tell, we are talking about repairing
a tool.

> Personally I've never had a tile come loose unless it
> was a partial tile and  came out sideways at the edge.

My experience so far as well. Tool I have came from California
and is believed to be hydrostone. Tiles lost are exclusively
on edges. All but one are tiles that were cut in half. This
tool was clearly channeled. Repair was done with urethane
glue, as I mentioned earlier in a different, related post.
This is to be used on a fine polished 12.5" F/5 that will
be brought down to ~F/3.9 for my Mak-Cass project.

Dominic


From brianb at myuw.net  Mon May 11 19:54:01 2009
From: brianb at myuw.net (brianb at myuw.net)
Date: Mon, 11 May 2009 03:54:01 -0700 (PDT)
Subject: [ATM] myth?
In-Reply-To: <4A07C68F.5010100@pacbell.net>
Message-ID: <Pine.LNX.4.43.0905110354010.891@hur12.myuw.net>


So if I wanted to see this effect for myself, what "technique" would I use to ensure zoning?



On Sun, 10 May 2009, Richard Ozer wrote:

> Yes! It's quite remarkable actually.
>
> brianb at myuw.net wrote:
>> 
>> 
>> All of the books say the grid pattern on a pitch lap should not be centered, 
>> as zoning will occur.
>> This doesn't seem right to me.
>> Can this really happen?
>> 
>> 
>> _______________________________________________
>> ATM mailing list http://www.atmlist.net/
>> 
>



From don.surles at verizon.net  Mon May 11 20:14:57 2009
From: don.surles at verizon.net (don surles)
Date: Mon, 11 May 2009 07:14:57 -0400
Subject: [ATM] myth?
In-Reply-To: <Pine.LNX.4.43.0905102203400.20647@hur12.myuw.net>
References: <Pine.LNX.4.43.0905102203400.20647@hur12.myuw.net>
Message-ID: <491798bed2ef1177773b8da404b72124@verizon.net>

I am not sure about the definition of "zoning" but centered patterns on 
a tool will definitely leave it's mark on your polished mirror...prove 
it for yourself so you will never doubt the wisdom of those who have 
"learned by doing".

i made a pitch lap and pressed the old Hex rubber mat pattern, 
centered, into the pitch.  My mirror took on the appearance of the 
bottom of a washtub...nice concentric rings.  A new lap with off-center 
square grid pattern cleaned up the washtub rings within an hour or 
so...lesson learned OJT.

BTW...I have never repeated the centered pitch lap pattern.

Don...


On May 11, 2009, at 1:03 AM, brianb at myuw.net wrote:

>
>
> All of the books say the grid pattern on a pitch lap should not be 
> centered, as zoning will occur.
> This doesn't seem right to me.
> Can this really happen?
>
>
> _______________________________________________
> ATM mailing list http://www.atmlist.net/
>
>
Don Surles


From rozer at pacbell.net  Mon May 11 23:07:51 2009
From: rozer at pacbell.net (Richard Ozer)
Date: Mon, 11 May 2009 07:07:51 -0700
Subject: [ATM] myth?
Message-ID: <200905111407.n4BE7ltT004162@njbrsmtp1.vzwmail.net>

Create a centered pitch lap and polish out with a center over center stroke

From f.franssen at planet.nl  Mon May 11 23:13:43 2009
From: f.franssen at planet.nl (Frans Franssen)
Date: Mon, 11 May 2009 16:13:43 +0200
Subject: [ATM] Bryan Greer
In-Reply-To: <mailman.736.1241999083.7676.atm@atmlist.net>
Message-ID: <CPSMTPM-EML108fiIBF00029464@CPSMTPM-EML108.kpnxchange.com>

Hello again

Perhaps I was not quite clear with my mail concerning the whereabouts of
Bryan Greer. I did know that he runs Protostar and that's why I ordered an
item from his list. After having communicated a few times by e-mail and
having paid my order by pay pal I did not hear again of him. That is about
two weeks now.  He also did not claim my payment, so that is not the
trouble. I applied to the atm list in order to find out if something had
happened to him. Thank you for any information. Regards, Frans

-----Original Message-----
From: atm-bounces at atmlist.net [mailto:atm-bounces at atmlist.net] On Behalf Of
atm-request at atmlist.net
Sent: Monday, May 11, 2009 1:45 AM
To: atm at atmlist.net
Subject: ATM Digest, Vol 65, Issue 8

Send ATM mailing list submissions to
	atm at atmlist.net

To subscribe or unsubscribe via the World Wide Web, visit
	http://www.atmlist.net/mailman/listinfo.cgi/atm
or, via email, send a message with subject or body 'help' to
	atm-request at atmlist.net

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	atm-owner at atmlist.net

When replying, please edit your Subject line so it is more specific
than "Re: Contents of ATM digest..."


Today's Topics:

   1. Bryan Greer (Frans Franssen)
   2. Diamond hone for beveling (TONY B)
   3. Re: Bryan Greer (Mark Holm)
   4. Re: Diamond hone for beveling (TONY BLAKESLEY)
   5. Duplov apochromat (Mircea Pteancu)
   6. Re: [Fwd: Re:  Polyurethane tiles] (Tom Stokes)
   7. Re: Lightweight glass (Bob May)
   8. Re: [Fwd: Re:  Polyurethane tiles] (Bob May)
   9. Re: Diamond hone for beveling (Bob May)
  10. David Davis lightweight blank I got. (Bob May)
  11. Re: Duplov apochromat (Bob May)
  12. Re: David Davis lightweight blank I got. (TONY B)
  13. Re: David Davis lightweight blank I got. (Vladimir Galogaza)
  14. Re: [Fwd: Re:  Polyurethane tiles] (chris forder)
  15. Re: Duplov apochromat (Jan Bentz)
  16. Re: Duplov apochromat (Richard in the UK)
  17. Re: [Fwd: Re:  Polyurethane tiles] (Bob May)
  18. Re: [Fwd: Re:  Polyurethane tiles] (hermit)
  19. Re: [Fwd: Re:  Polyurethane tiles] (Berthold Hamburger)
  20. Re: [Fwd: Re:  Polyurethane tiles] (Tom Stokes)
  21. Re: [Fwd: Re:  Polyurethane tiles] (Jarvis Krumbein)


----------------------------------------------------------------------

Message: 1
Date: Sat, 9 May 2009 16:19:01 +0200
From: "Frans Franssen" <f.franssen at planet.nl>
To: "'ATMList'" <atm at atmlist.net>
Subject: [ATM] Bryan Greer
Message-ID:
	<CPSMTPM-EML110edC8m0001768a at CPSMTPM-EML110.kpnxchange.com>
Content-Type: text/plain;	charset="us-ascii"

Hello to all,
 
Does anybody out there know the whereabouts of Bryan Greer, the one who has
published several articles in S & T about air currents in telescopes. He
doesn't react to my e-mails. Thank you for any info. F. Franssen.


------------------------------

Message: 2
Date: Sat, 09 May 2009 09:21:29 CDT
From: "TONY B" <blaktony86 at yahoo.com>
To: atm at atmlist.net
Subject: [ATM] Diamond hone for beveling
Message-ID: <mailman.680.1241878893.7676.atm at atmlist.net>
Content-Type: text/plain; charset="iso-8859-1"

Well i found the diamond hone set at harbor freight. I will now attempt to
bevel. Wish me luck!! 



------------------------------

Message: 3
Date: Sat, 09 May 2009 10:40:03 -0400
From: Mark Holm <holmmarkd at gmail.com>
To: 'ATMList' <atm at atmlist.net>
Subject: Re: [ATM] Bryan Greer
Message-ID: <4A0595C3.9090504 at gmail.com>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed

Bryan used to work at FPI-Protostar.  I don't know if he still does.  
You could try there.   protostar at fpi-protostar.com 
<mailto:protostar at fpi-protostar.com>

Frans Franssen wrote:
> Hello to all,
>  
> Does anybody out there know the whereabouts of Bryan Greer, the one who
has
> published several articles in S & T about air currents in telescopes. He
> doesn't react to my e-mails. Thank you for any info. F. Franssen.
> _______________________________________________
> ATM mailing list http://www.atmlist.net/
>   


-- 
Mark Holm
markholm at verizon.net
holmmarkd at gmail.com



------------------------------

Message: 4
Date: Sat, 9 May 2009 10:09:09 -0700 (PDT)
From: TONY BLAKESLEY <blaktony86 at yahoo.com>
To: atm at atmlist.net
Subject: Re: [ATM] Diamond hone for beveling
Message-ID: <64603.30505.qm at web81905.mail.mud.yahoo.com>
Content-Type: text/plain; charset=iso-8859-1

WOW,
?
I must say this is the best procedure for beveling. I completely beveled
front and back side of my 9.2" mirror in about an hour. There were no flakes
or scallops produced from the bevel. I beveled the mirror using the diamond
hone @ a 45 degree angle and applied pressure only to the downward strokes.
It really is like cutting butter. No grit either to scratch mirror. I had a
completely polished surface and didnt find one scratch. I did have my mirror
wet the entire time by squirting water while grinding the bevel.
?
Thanks guys for the tip! Now I can go ahead and hopefully polish the surface
without it sticking. 
?
Oh yeah I forgot to mention, The little pit/chip was actually a white
impurity in the mirror. It wasnt a bubble but I got past it and hopefully I
can polish/figure the mirror without it catching. I think it messed up the
figure around this little impurity, but hopefully it can be easily worked
out since it was such a tiny object (less than 1/8" long).
?
-Tony

--- On Sat, 5/9/09, TONY B <blaktony86 at yahoo.com> wrote:

From: TONY B <blaktony86 at yahoo.com>
Subject: [ATM] Diamond hone for beveling
To: atm at atmlist.net
Date: Saturday, May 9, 2009, 9:21 AM

Well i found the diamond hone set at harbor freight. I will now attempt to
bevel. Wish me luck!! 

_______________________________________________
ATM mailing list http://www.atmlist.net/


------------------------------

Message: 5
Date: Sat, 9 May 2009 12:03:19 -0700 (PDT)
From: Mircea Pteancu <mirceapte at yahoo.com>
To: atm at atmlist.net
Subject: [ATM] Duplov apochromat
Message-ID: <97935.27579.qm at web35807.mail.mud.yahoo.com>
Content-Type: text/plain; charset=iso-8859-1

Hello
I have only mirrors,the most ''complex'' lense I own?is a 60mm dublet?of
310mm f'.l.
I joined this list one and half years ago and I?don't remember? references
to such apochromats using normal,or only slightly exotic?optical
glasses.Maybe some of you will find this article? as interesting.It
was?brought to my attention by zoth,a colleague moderator on our Romanian
forum ''astronomy.ro''.?
http://bossanova9.org/astro/optics/normal%20glass%20apo%20-%20duplov.pdf
?
Regards,Mircea


      

------------------------------

Message: 6
Date: Sat, 9 May 2009 14:42:22 -0700
From: "Tom Stokes" <tstokes at pacbell.net>
To: "Mark Holm" <holmmarkd at gmail.com>,	"Michael Coslo" <mjc5 at psu.edu>
Cc: ATM List <atm at atmlist.net>
Subject: Re: [ATM] [Fwd: Re:  Polyurethane tiles]
Message-ID: <C14EBA31D1AD43A199AF6E55BCE2611A at tom>
Content-Type: text/plain; format=flowed; charset="iso-8859-1";
	reply-type=original

For what it is worth, this is a picture of a tile-in-plaster tool I made
circa '69 or '70 for a 5" Mak corrector.

http://www.mirrorgrindingmachine.com/transient/DSCN0070.JPG

I used to have the matching concave tool but I ground through the tiles
during fine grinding and threw it away. Chickened out and went on to another
project.

I do vaguely remember that I cast the plaster base against the molded blank,
epoxied on the tiles, and filled the channels with plaster.

Tom Stokes

----- Original Message ----- 
From: "Mark Holm" <holmmarkd at gmail.com>
To: "Michael Coslo" <mjc5 at psu.edu>
Cc: "ATM List" <atm at atmlist.net>
Sent: Friday, May 08, 2009 5:39 PM
Subject: Re: [ATM] [Fwd: Re: Polyurethane tiles]


>
> The tile-in-stone method is not very old, perhaps around a decade. (I
> certainly did not invent it.)
>
> In fact, the glue-tile-on-plaster method is older, by a decade or two.  I
> distinctly remember an article about it in S&T in the late 80's.  It was
> touted then, as a revolutionary replacement for solid glass tools.   When
> I recommend the tile-in-stone method, I am actually being avant-garde
> compared to the dinosaurs who recommend epoxying tile to tools  ;)




------------------------------

Message: 7
Date: Sat, 9 May 2009 16:10:07 -0700
From: "Bob May" <rmay at nethere.com>
To: "Guy Brandenburg" <gfbrandenburg at yahoo.com>,	<atm at atmlist.net>
Subject: Re: [ATM] Lightweight glass
Message-ID: <000601c9d0fb$4c30b900$8f78fea9 at amd>
Content-Type: text/plain;	charset="iso-8859-1"

Guy, Richard's glass was pretty easy to grind.  It's problem is
that it is somewhat sensitive to temps so you can't just throw
some pitch on it or it will then crack.  Richard did several
samples and I found him up at RTMC ahd discussed the problems he
had and told him that I could polish out the last one he had.
Technique on putting the pitch was to put everything under water
and heat it up on the stove (no wife, no problem!)  Used a mold
that I made (silicone rubber with holes punched in it which made
for buttons of pitch to the glass surface.  Letting things cool
after the pitch mostly made it to the glass and I had a pitch lap
which I then used to polish the glass out.  Put a nice surface on
it and took it up to RTMC the next year, showed it around and
found Richard and passed it on to him.  From what I have heard
from him is that his wife now has that mirror in a telescope
(ref. the paint incompaibilities he had a while ago with
polyurethane paint that didn't dry from the stain he used).
It was a nice interesting project!
See the post on David Davis's mirror for more fun.
Bob May

rmay at nethere.com
http: slash /nav.to slash bobmay
http: slash /bobmay dot astronomy.net




------------------------------

Message: 8
Date: Sat, 9 May 2009 16:14:45 -0700
From: "Bob May" <rmay at nethere.com>
To: <atm at atmlist.net>
Subject: Re: [ATM] [Fwd: Re:  Polyurethane tiles]
Message-ID: <000f01c9d0fb$f1c8b0c0$8f78fea9 at amd>
Content-Type: text/plain;	charset="iso-8859-1"

IF YOU USE THE TILE TOOL TO DO THE INITIAL CARVING, YOU WILL FIND
IT BETTER TO DO THE TILES ON EDGE!!!   Do the initial hole
carving (generating the curve) with iron tools or diamond tools
and there will be a lot less need for the thickness of the tiles.
If you do a good job of getting a spherical surface according to
a spherometer (within a thousandths or three) over the surface,
you should be able to do 3 or 4 mirrors with the same tool
without any worry.
Bob May

rmay at nethere.com
http: slash /nav.to slash bobmay
http: slash /bobmay dot astronomy.net




------------------------------

Message: 9
Date: Sat, 9 May 2009 16:34:47 -0700
From: "Bob May" <rmay at nethere.com>
To: <atm at atmlist.net>
Subject: Re: [ATM] Diamond hone for beveling
Message-ID: <002001c9d0fe$be077480$8f78fea9 at amd>
Content-Type: text/plain;	charset="iso-8859-1"

An inclusin in the glass will make for fun as it is probably
going to be harder than the glass itself.  You did the right
thing by grinding it out of the glass.
Bob May

rmay at nethere.com
http: slash /nav.to slash bobmay
http: slash /bobmay dot astronomy.net




------------------------------

Message: 10
Date: Sat, 9 May 2009 17:00:29 -0700
From: "Bob May" <rmay at nethere.com>
To: <atm at atmlist.net>
Subject: [ATM] David Davis lightweight blank I got.
Message-ID: <003401c9d102$55375840$8f78fea9 at amd>
Content-Type: text/plain;	charset="iso-8859-1"

Opened the box from David and found a very lightweight 8" blank
of his attempt at an ultralightweight blank.
First was to measure to find what kind of ROC I got.  It is about
21" FL so it is going to be some fun!  The front surface appears
to be single thickness glass (regular window glass!) backed up by
a glass foam so that the whole thing appears to be about a full
thickness blank.  The front surface appears to be glued to the
foam with gorilla glue or something like that.
The front surface wasn't a good sphere so I had to spend some
time making it spherical but it was interesting to watch the hole
in the middle disappear along with the TDE.  At this point, I've
gotten 120 grit done.  Next week is going down through the grits.
Week after that is RTMC so I'll be up there on Sat. and will have
the blank available for viewing.
The blank is so light that I let it float in the wash water and
it only went in about 1/4" or less!!!
Bob May

rmay at nethere.com
http: slash /nav.to slash bobmay
http: slash /bobmay dot astronomy.net




------------------------------

Message: 11
Date: Sat, 9 May 2009 17:18:31 -0700
From: "Bob May" <rmay at nethere.com>
To: <atm at atmlist.net>
Subject: Re: [ATM] Duplov apochromat
Message-ID: <003501c9d104$d9f5aa80$8f78fea9 at amd>
Content-Type: text/plain;	charset="iso-8859-1"

The problem with optical glasses (glass in general actually) is
that the dispersion curves are just that, curves, and as a
result, it is difficult to get two curves that match their slopes
so that the light is properly refracted to the same spot.  The
errors aren't large but they are there.  The exitic glasses do
have their curves different from "normal" glasses (the normal
glasses are glasses that conform to a curve in the Nd/Vd chart)
in that the dispersion is different from what the normal line of
glasses is.  This makes it possible to better match the amount of
dispersion of the light to another glass over the spectrum of
light.  Needless to say, the obtaining of an exact match between
the dispersions of the various glasses is an almost impossible
task.
What makes things easier tho is to use more glasses which can
then compensate better for color errors.  Using 5 or more glass
pieces improves this a lot over the 2 glass doublets.  The
article shows 3 sets of glasses to obtain a high quality of
compliance of the dispersion of the light.  Unfortunately, what
happens is that each surface of the glass (uncoated glass)
reflects about 4% of the light so having 10 surfaces will mean a
large loss of light.  For planetary viewing, that isn't so bad
but still losing almost a magnitude of light is a big loss for a
star viewing telescope, not so bad with a planetary telescope.
I'll note that you do want to do large magnifications when
looking at planets so that means that a design of a larger
(150-250mm) aperture and a longer FL.  The larger aperture makes
matching glass harder but the longer FL makes it easier and I
will comment here that focal lengths on the order of 5 meters
will make for an excellent telescope for planetary viewing as the
image scale (how big things are at the focal plane of the
telescope) is larger which means that you can use larger EPs that
have better control of the aberrations that happen in the EP.
Good luck!
Bob May

rmay at nethere.com
http: slash /nav.to slash bobmay
http: slash /bobmay dot astronomy.net




------------------------------

Message: 12
Date: Sat, 09 May 2009 19:58:25 CDT
From: "TONY B" <blaktony86 at yahoo.com>
To: atm at atmlist.net
Subject: Re: [ATM] David Davis lightweight blank I got.
Message-ID: <mailman.702.1241917109.7676.atm at atmlist.net>
Content-Type: text/plain; charset="iso-8859-1"

 Id like to see a picture of that!
-----Original Message-----
Date: Saturday, May 09, 2009 6:57:52 pm
To: <atm at atmlist.net>
From: "Bob May" <rmay at nethere.com>
Subject: [ATM] David Davis lightweight blank I got.

Opened the box from David and found a very lightweight 8" blank
of his attempt at an ultralightweight blank.
First was to measure to find what kind of ROC I got.  It is about
21" FL so it is going to be some fun!  The front surface appears
to be single thickness glass (regular window glass!) backed up by
a glass foam so that the whole thing appears to be about a full
thickness blank.  The front surface appears to be glued to the
foam with gorilla glue or something like that.
The front surface wasn't a good sphere so I had to spend some
time making it spherical but it was interesting to watch the hole
in the middle disappear along with the TDE.  At this point, I've
gotten 120 grit done.  Next week is going down through the grits.
Week after that is RTMC so I'll be up there on Sat. and will have
the blank available for viewing.
The blank is so light that I let it float in the wash water and
it only went in about 1/4" or less!!!
Bob May

rmay at nethere.com
http: slash /nav.to slash bobmay
ht



------------------------------

Message: 13
Date: Sun, 10 May 2009 09:45:40 +0200
From: "Vladimir Galogaza" <vladimir.galogaza1 at zg.t-com.hr>
To: "ATM List" <atm at atmlist.net>
Subject: Re: [ATM] David Davis lightweight blank I got.
Message-ID: <3D6D1A3FBB7A495BA68A169423D46E95 at piv555a133b59e>
Content-Type: text/plain; format=flowed; charset="ISO-8859-1";
	reply-type=original

Bob and David,

I am very interested in having this 8" foam backed 21" FL mirror
for testing with PSI-Bath interferometer.

Would it be possible to get it after you are finished with RTMC and
possibly some other projects in the future.

I can use it weather spherical or paraboloidal or anything in between
(or outside).

If  you will consider it would it be possible to have it coated before 
sending to me.

Regards
Vladimir. 



------------------------------

Message: 14
Date: Sun, 10 May 2009 11:35:27 +0200
From: chris forder <camkit at mweb.co.za>
To: atm at atmlist.net
Subject: Re: [ATM] [Fwd: Re:  Polyurethane tiles]
Message-ID: <4A069FDF.1070406 at mweb.co.za>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed

My personal choice is to epoxy the tiles to a cement tool. The channels 
are there and you can see how nuch tile thickness remains.
I always rough out the sag on the mirror with a large angle grinder. 
That way less tool is used in your mirror making. My tiles are made of 
floor tiles and last for about three or four mirrors of the same size & sag.

Chris Cape Town


------------------------------

Message: 15
Date: Sun, 10 May 2009 10:06:35 -0700
From: Jan Bentz <jbentz at inreach.com>
To: Mircea Pteancu <mirceapte at yahoo.com>
Cc: atm at atmlist.net
Subject: Re: [ATM] Duplov apochromat
Message-ID: <4A07099B.2070900 at inreach.com>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed

Mircea Pteancu wrote:

>Hello
>I have only mirrors,the most ''complex'' lense I own is a 60mm dublet of
310mm f'.l.
>I joined this list one and half years ago and I don't remember  references
to such apochromats using normal,or only slightly exotic optical
glasses.Maybe some of you will find this article  as interesting.It was
brought to my attention by zoth,a colleague moderator on our Romanian forum
''astronomy.ro''. 
>http://bossanova9.org/astro/optics/normal%20glass%20apo%20-%20duplov.pdf
> 
>Regards,Mircea
>
>
>      
>_______________________________________________
>ATM mailing list http://www.atmlist.net/
>
>  
>
Mircea -- I raytraced all three of the systems described and they all 
appeared to do what is claimed in the paper.  Some problems were left 
out of the description however.  Aside from the obvious construction 
problems these systems all have a fairly small field of high quality and 
are all 1.5 to 2.5 times longer than their focal length.  The curvature 
of field ranges from about -150 to -200mm but is largely compensated for 
by alot of astigmatism.  I have not done a tolerance analysis but the 
concentricity would be very critical because of the widely separated 
components.  Some of the elements are cemented so the loss of light 
would not be quite so high as Bob May implied.   The usual trouble with 
widely separated component systems where each component is not 
seperately achromatised  is the large chromatic differance of 
magnification (lateral color) but  these designs ingeniously correct for 
that.  They would certainly be suitable for a planetary scope if 
properly constructed - a big if.

Jan Bentz


------------------------------

Message: 16
Date: Sun, 10 May 2009 19:03:26 +0100
From: Richard in the UK <richard at foucault.co.uk>
To: Jan Bentz <atm at atmlist.net>
Subject: Re: [ATM] Duplov apochromat
Message-ID: <1983857769.20090510190326 at foucault.co.uk>
Content-Type: text/plain; charset=us-ascii

Hello Jan,

Sunday, May 10, 2009, 6:06:35 PM, you wrote:

> these systems all have a fairly small field of high quality


I would call it a very limited field. The errors of the 90mm f/7 start
increasing very quickly once the field is more than 5mm diameter. Do a
direct comparison of the 90mm f/7 with a 90mm f/7 Newtonian and, over
the very limited field that this "apo" has, you will see little
difference. In fact, paraxially, the newt outperforms it. For 14
optical surfaces, I would have expected more.

-- 
Best regards,
 Richard in the UK



------------------------------

Message: 17
Date: Sun, 10 May 2009 14:33:51 -0700
From: "Bob May" <rmay at nethere.com>
To: <atm at atmlist.net>
Subject: Re: [ATM] [Fwd: Re:  Polyurethane tiles]
Message-ID: <000601c9d1b7$03edb460$8f78fea9 at amd>
Content-Type: text/plain;	charset="iso-8859-1"

One thing that I'm having trouble understanding is why there
needs to be channels on the tool???  Before the tile tool
evolution, nobody did channels in the second piece of glass that
was used as the tool!  Even the channeling that Newport does with
their tool blanks is a fairly new thing.  Can anybody enlighten
me as to why this has started?  I don't believe that the grit
resovoir thing is valid as the grit all falls to the bottom of
the channel and fails to then get to the grinding surface.
Bob May

rmay at nethere.com
http: slash /nav.to slash bobmay
http: slash /bobmay dot astronomy.net




------------------------------

Message: 18
Date: Sun, 10 May 2009 18:01:05 -0400
From: hermit <hermit at outofoptions.org>
Cc: atm at atmlist.net
Subject: Re: [ATM] [Fwd: Re:  Polyurethane tiles]
Message-ID: <4A074EA1.1000603 at outofoptions.org>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed

Bob May wrote:
> One thing that I'm having trouble understanding is why there
> needs to be channels on the tool???  Before the tile tool
> evolution, nobody did channels in the second piece of glass that
> was used as the tool!  Even the channeling that Newport does with
> their tool blanks is a fairly new thing.  Can anybody enlighten
> me as to why this has started?  I don't believe that the grit
> resovoir thing is valid as the grit all falls to the bottom of
> the channel and fails to then get to the grinding surface.
> Bob May
>
>   
Less sticking and easier to remove.  If you watch through the back of 
the glass, you will see that the grit doesn't all fall the way you might 
think.  Plus tiles come in little squares that are easy to work with. ;)

Ken Lowther


------------------------------

Message: 19
Date: Mon, 11 May 2009 00:10:36 +0200
From: "Berthold Hamburger" <b-hamburger at ya.com>
To: <atm at atmlist.net>
Subject: Re: [ATM] [Fwd: Re:  Polyurethane tiles]
Message-ID: <000401c9d1bc$267309e0$73591da0$@com>
Content-Type: text/plain;	charset="us-ascii"

By intuition, I would say that the channels create many individual grinding
edges that all do their job of biting into the glass. Especially since all
edges are automatically coated with grit when grinding TOT. When grinding
MOT I would suspect that grit is washed to the top of the tool by turbulence
due to the motion of liquid/water through the channels.
An analogy would be trying to cut through a piece of wood with a knife
(unchanneled tool) and then try the same thing with a serrated blade
(channeled tool). The latter will do the job faster without doubt.

Berthold

-- 
Berthold Hamburger - Cellist/Spain
Email: behambu at artinso.com
http://www.artinso.com
http://www.astro.artinso.com

> -----Original Message-----
> From: atm-bounces at atmlist.net [mailto:atm-bounces at atmlist.net] On Behalf
> Of Bob May
> Sent: domingo, 10 de mayo de 2009 23:34
> To: atm at atmlist.net
> Subject: Re: [ATM] [Fwd: Re: Polyurethane tiles]
> 
> One thing that I'm having trouble understanding is why there
> needs to be channels on the tool???  Before the tile tool
> evolution, nobody did channels in the second piece of glass that
> was used as the tool!  Even the channeling that Newport does with
> their tool blanks is a fairly new thing.  Can anybody enlighten
> me as to why this has started?  I don't believe that the grit
> resovoir thing is valid as the grit all falls to the bottom of
> the channel and fails to then get to the grinding surface.
> Bob May
> 
> rmay at nethere.com
> http: slash /nav.to slash bobmay
> http: slash /bobmay dot astronomy.net
> 
> 
> _______________________________________________
> ATM mailing list http://www.atmlist.net/



------------------------------

Message: 20
Date: Sun, 10 May 2009 16:23:32 -0700
From: "Tom Stokes" <tstokes at pacbell.net>
To: "Bob May" <rmay at nethere.com>,	<atm at atmlist.net>
Subject: Re: [ATM] [Fwd: Re:  Polyurethane tiles]
Message-ID: <1ECC27978CBC48D6B74CA578614C175A at tom>
Content-Type: text/plain; format=flowed; charset="iso-8859-1";
	reply-type=original

Bob, I'm using a MOM 20. Are you suggesting that I do this by hand or build
another machine? Granted, using abrasives on a spinning mirror does not
lead to fast hogging, but it is awfully easy to glue on another layer of
tiles and keep on trucking. We are talking an extra day or two at most. I'm
planning on making one mirror, not 3 or 4. When I do make another mirror, it
will almost certainly be a different diameter and ROC.

Tom Stokes
http://www.mirrorgrindingmachine.com/

----- Original Message ----- 
From: "Bob May" <rmay at nethere.com>
To: <atm at atmlist.net>
Sent: Saturday, May 09, 2009 4:14 PM
Subject: Re: [ATM] [Fwd: Re: Polyurethane tiles]


> IF YOU USE THE TILE TOOL TO DO THE INITIAL CARVING, YOU WILL FIND
> IT BETTER TO DO THE TILES ON EDGE!!!   Do the initial hole
> carving (generating the curve) with iron tools or diamond tools
> and there will be a lot less need for the thickness of the tiles.
> If you do a good job of getting a spherical surface according to
> a spherometer (within a thousandths or three) over the surface,
> you should be able to do 3 or 4 mirrors with the same tool
> without any worry.
> Bob May
>
> rmay at nethere.com
> http: slash /nav.to slash bobmay
> http: slash /bobmay dot astronomy.net
>
>
> _______________________________________________
> ATM mailing list http://www.atmlist.net/




------------------------------

Message: 21
Date: Sun, 10 May 2009 16:43:41 -0700
From: Jarvis Krumbein <jkoptic at juno.com>
To: rmay at nethere.com
Cc: atm at atmlist.net
Subject: Re: [ATM] [Fwd: Re:  Polyurethane tiles]
Message-ID: <20090510.164341.2896.0.jkoptic at juno.com>
Content-Type: text/plain

Bob, I always cut a few channels in my solid glass tools to prevent
sticking.  I started doing this in 1947 after a horrendus experience
working my first 12" by hand.  If you've never had a tool and mirror
suddenly firmly stuck together while in the last stage of fine grinding
you haven't lived.  It took me two weeks to get them apart and every tool
had at least one channel quickly ground in after that just to relieve the
suction.  Go back to the old ATM books to get an idea as to how much of a
problem this sometime was and for some of the novel methods of getting
two discs apart.

Jarvis Krumbein

On Sun, 10 May 2009 14:33:51 -0700 "Bob May" <rmay at nethere.com> writes:
> One thing that I'm having trouble understanding is why there
> needs to be channels on the tool???  Before the tile tool
> evolution, nobody did channels in the second piece of glass that
> was used as the tool!  Even the channeling that Newport does with
> their tool blanks is a fairly new thing.  Can anybody enlighten
> me as to why this has started?  I don't believe that the grit
> resovoir thing is valid as the grit all falls to the bottom of
> the channel and fails to then get to the grinding surface.
> Bob May
> 
> rmay at nethere.com
> http: slash /nav.to slash bobmay
> http: slash /bobmay dot astronomy.net
> 
> 
> _______________________________________________
> ATM mailing list http://www.atmlist.net/
> 

____________________________________________________________
Advance your tech career with a master's in IT!
http://thirdpartyoffers.juno.com/TGL2141/fc/BLSrjpTEgrEihBaJYdUIEbiwsSrrtsCr
yiXQCYaBvwZZZpurEsSqGez2EXe/


------------------------------

_______________________________________________
ATM mailing list http://www.atmlist.net/

End of ATM Digest, Vol 65, Issue 8
**********************************


From al at sgi.com  Mon May 11 23:23:19 2009
From: al at sgi.com (Alexis Cousein)
Date: Mon, 11 May 2009 16:23:19 +0200
Subject: [ATM] Bryan Greer
In-Reply-To: <CPSMTPM-EML108fiIBF00029464@CPSMTPM-EML108.kpnxchange.com>
References: <CPSMTPM-EML108fiIBF00029464@CPSMTPM-EML108.kpnxchange.com>
Message-ID: <4A0834D7.90905@sgi.com>

Frans Franssen wrote:
> Hello again
> 
> Perhaps I was not quite clear with my mail concerning the whereabouts of
> Bryan Greer. I did know that he runs Protostar and that's why I ordered an
> item from his list. After having communicated a few times by e-mail and
> having paid my order by pay pal I did not hear again of him. That is about
> two weeks now.  He also did not claim my payment, so that is not the
> trouble. I applied to the atm list in order to find out if something had
> happened to him. Thank you for any information. Regards, Frans
> 
You could give them a ring at +1 614 785 0245.


From brianb at myuw.net  Tue May 12 00:51:40 2009
From: brianb at myuw.net (brianb at myuw.net)
Date: Mon, 11 May 2009 08:51:40 -0700 (PDT)
Subject: [ATM] myth?
In-Reply-To: <200905111407.n4BE7ltT004162@njbrsmtp1.vzwmail.net>
Message-ID: <Pine.LNX.4.43.0905110851400.18470@hur12.myuw.net>


Thanks, I'll give it a shot.
Seems like the center over center is important.
Brian


On Mon, 11 May 2009, Richard Ozer wrote:

> Create a centered pitch lap and polish out with a center over center stroke



From rmay at nethere.com  Tue May 12 05:06:37 2009
From: rmay at nethere.com (Bob May)
Date: Mon, 11 May 2009 13:06:37 -0700
Subject: [ATM] [Fwd: Re:  Polyurethane tiles]
References: <4A069FDF.1070406@mweb.co.za> <000601c9d1b7$03edb460$8f78fea9@amd>
	<4A074EA1.1000603@outofoptions.org>
Message-ID: <000c01c9d273$fe330bc0$8f78fea9@amd>

Ken, I have looked through the glass and looked at the grit/glass
that gets washed off of the tool afterwords.  Everything that
starts out in a groove stays there.  Much of what is on the tiles
falls down after a roll or two.  Unused grit that gets recovered
from the wash water ends up being on the order of 90% or more
whereas a solid tool produces about 10% unused grit.  Not all
that good on using the grit when channeled tools are used.
The Newport "channeling" doesn't help with the vacuum problem all
that much as there is no point where the channel gets to the
outside of the tool.  Fill the channel with water and you get a
nice lock.  I occasionally do channel a tile tool but that is
just a scratch from the center to the edge of the tool, just for
an air passage rather than a deep channel for holding grit.
Bob May

rmay at nethere.com
http: slash /nav.to slash bobmay
http: slash /bobmay dot astronomy.net



From rmay at nethere.com  Tue May 12 05:11:45 2009
From: rmay at nethere.com (Bob May)
Date: Mon, 11 May 2009 13:11:45 -0700
Subject: [ATM] [Fwd: Re:  Polyurethane tiles]
References: <4A038B44.6040401@gmail.com><C248E9F6FACC4A7188C1437A70885CE1@tom><DA1A8CCD-569F-461D-92B5-C9680ACD09D9@psu.edu><B7205FD67ECD4599947682DC15FC81D8@tom>
	<000f01c9d0fb$f1c8b0c0$8f78fea9@amd>
	<5CE8A56D04B24E569FC3E64983180E6E@tom>
Message-ID: <001101c9d274$b640a920$8f78fea9@amd>

With a MOM, I'd be using a diamond cutting wheel backed up by
something like an old speaker magnet and letting the side of the
cutting wheel (not standing the wheel up and using the edge but
rather laying down on the glass) and moving the wheel
occasionally (only a minimal stroke is needed) to keep the
surface sort of spherical.
The other is to just use a piece of iron or other brass to do the
carving, again doing zones more than the whole mirror at one time
with the grit of your choice.
Bob May

rmay at nethere.com
http: slash /nav.to slash bobmay
http: slash /bobmay dot astronomy.net



From rmay at nethere.com  Tue May 12 05:15:44 2009
From: rmay at nethere.com (Bob May)
Date: Mon, 11 May 2009 13:15:44 -0700
Subject: [ATM] [Fwd: Re:  Polyurethane tiles]
References: <20090510.164341.2896.0.jkoptic@juno.com>
Message-ID: <001801c9d275$447821a0$8f78fea9@amd>

I guess that one of the problems here is what is a "channel".
Everything that  I've seen is big canyons of a channel, so big in
many cases that the channels can hold a half pound of grit on an
8" mirror!  For me, all that is needed to prevent vacuum locking
(been there and had that happen a lot iwth some of the first
timers) is to put a scratch on the tool that may be 0.010" deep
and about as wide.  Just enough to allow the air to get into the
center of the surface.
Bob May

rmay at nethere.com
http: slash /nav.to slash bobmay
http: slash /bobmay dot astronomy.net



From rmay at nethere.com  Tue May 12 05:21:05 2009
From: rmay at nethere.com (Bob May)
Date: Mon, 11 May 2009 13:21:05 -0700
Subject: [ATM] [Fwd: Re:  Polyurethane tiles]
References: <4A069FDF.1070406@mweb.co.za> <000601c9d1b7$03edb460$8f78fea9@amd>
	<CD74BA23C5FA4AC78DABD64B4E743BA2@tom>
Message-ID: <001d01c9d276$03d2f2a0$8f78fea9@amd>

Polishing is done a bit differently than grinding.  You need to
bring up fresh CeO from the mix and, since CeO doesn't sink
anywhere near as fast as much larger grit, the more edges that
you have, the more polishing agent gets up to the pitch surface
and embeds itself.  Remember that polishing is more shaving the
glass of than cracking it off.  With the grit, having a large
single surface allows the grit to roll for a good distance,
making a lot of pits as it rolls along.  CeO gets embedded in the
pitch and provides a cutting edge that shaves the glass off of
the surface.
Bob May

rmay at nethere.com
http: slash /nav.to slash bobmay
http: slash /bobmay dot astronomy.net



From wa4guu at verizon.net  Tue May 12 05:18:50 2009
From: wa4guu at verizon.net (Jerry)
Date: Mon, 11 May 2009 16:18:50 -0400
Subject: [ATM] Polyurethane tiles
Message-ID: <7A278EBA991041CAB02D0E2C77C1062B@D85SJB21>

Working MOT, turbulence of the water in the channels keeps grit coming up
and between the tool and glass.  But that is because I wrap the tool in a
piece of paper tape that holds the water and grit in the tool.  The tape is
ground away maintaining it's level with the height of the edge tiles. Wets
last a long time and the grit gets used as efficiently, and probably more
so, as any other way I know of.

 

TOT works well also but obviously as the tool is stroked over the edge of
the mirror some water and grit is lost, but that is true with other methods
also. There is a tendency for the water to pool at the center of a concave
mirror if it is level.

 

Jerry

 


From rmay at nethere.com  Tue May 12 05:27:38 2009
From: rmay at nethere.com (Bob May)
Date: Mon, 11 May 2009 13:27:38 -0700
Subject: [ATM] Polyurethane tiles
References: <Pine.LNX.4.44.0905110958320.28033-100000@uno.canit.se>
Message-ID: <003801c9d276$f1bae0e0$8f78fea9@amd>

Channeling is another problem with doing tiles in the tool.  As
you channel, you often want to make sure you have Grand Canyons
of channels so you weaken the stone by removing most of the stone
from the sides of the tiles and thus, the tiles can then break
off the little bit left and next thing you know is that there is
no tile where it belongs!  Even a matted tile will break loose if
you channel a lot.  The whole retaining of the tile in the tool
is mechanical clamping and not actual "gluing" of the two
surfaces together.
Bob May

rmay at nethere.com
http: slash /nav.to slash bobmay
http: slash /bobmay dot astronomy.net



From russjocoy at hotmail.com  Tue May 12 09:32:33 2009
From: russjocoy at hotmail.com (Russell Jocoy)
Date: Mon, 11 May 2009 20:32:33 -0400
Subject: [ATM] David Davis, pushing the envelope
Message-ID: <COL116-W542F1B7C9E6A0C1A148CFFB8600@phx.gbl>


 

 

   To all on the list, I would like to congradulate David Davis for his continueing drive to push the envelope. His new idea is still unfound, and could turn out to be unaceptable as a lightwieght alternative to heavy telescope mirrors.  Whether we do it or the "big" funded companies do it, is the question.... This list is made up of dedicated amature scientist's in their on right. Many on this list have done things that professional engineer's and scientist's look and wonder, they have been backed by big money, we are backed by desire and outcome and the local surplus suppliers.  We all are directed to a central point...Create an optic to see the stars, create an optic that will not break your back to move, create an optic that is to the limit of diffraction, and light enough for us to move around to different locations.  David is thinking of how we can make light weight optic to put into space, your space, outerspace, myspace.... Keep on truckin"  David............Russ Jocoy

ZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZzzz

_________________________________________________________________
Windows Live?: Keep your life in sync.
http://windowslive.com/explore?ocid=TXT_TAGLM_BR_life_in_synch_052009

From shane at ct-astronomer.com  Tue May 12 09:59:10 2009
From: shane at ct-astronomer.com (Shane LaPierre)
Date: Mon, 11 May 2009 20:59:10 -0400
Subject: [ATM] David Davis, pushing the envelope
In-Reply-To: <COL116-W542F1B7C9E6A0C1A148CFFB8600@phx.gbl>
References: <COL116-W542F1B7C9E6A0C1A148CFFB8600@phx.gbl>
Message-ID: <636ECCA1-03C4-471C-98E0-E9F30A692A43@ct-astronomer.com>

Is there already a patent on this process?  Just wondering if  
commercial motivations are protected by a patent already...  Check out  
the link below:

http://www.freepatentsonline.com/4670338.html

Shane

On May 11, 2009, at 8:32 PM, Russell Jocoy wrote:

>
>
>
>
>
>   To all on the list, I would like to congradulate David Davis for  
> his continueing drive to push the envelope. His new idea is still  
> unfound, and could turn out to be unaceptable as a lightwieght  
> alternative to heavy telescope mirrors.  Whether we do it or the  
> "big" funded companies do it, is the question.... This list is made  
> up of dedicated amature scientist's in their on right. Many on this  
> list have done things that professional engineer's and scientist's  
> look and wonder, they have been backed by big money, we are backed  
> by desire and outcome and the local surplus suppliers.  We all are  
> directed to a central point...Create an optic to see the stars,  
> create an optic that will not break your back to move, create an  
> optic that is to the limit of diffraction, and light enough for us  
> to move around to different locations.  David is thinking of how we  
> can make light weight optic to put into space, your space,  
> outerspace, myspace.... Keep on truckin"  David............Russ Jocoy


From toolontop at yahoo.com  Tue May 12 13:52:43 2009
From: toolontop at yahoo.com (Mark Cowan)
Date: Mon, 11 May 2009 21:52:43 -0700 (PDT)
Subject: [ATM] Polisher faceting was Re:  myth?
Message-ID: <598596.36880.qm@web90405.mail.mud.yahoo.com>


With centered facets you're much more likely to see zoning as well as an imprint of the faceting pattern on the glass (primary ripple).  But why would this be a myth?  It's more like one of the 11 commandments.  

But (sacrilege!) there are better ways to facet a polisher, look at these: 

http://raddobs.com/atm/6inch_parab.jpg  
http://raddobs.com/atm/nonperiodic_spin_polish_example.jpg  

Good examples of the nonperiodic faceting I've used on all polishers for years.  Never get tool imprints with these!

The first is a 6" figuring tool from very soft pitch, tempered Gugolz 55, and the second is a 12" or so Acculap tool for machine polishing.  The pattern is easy to layout and maintain.

OTOH if you what you _want_ is zoning, be sure to use smaller facets (error #1), lay them out in rows with a ruler (error #2), all exactly the same size (error #3), and center the middle one precisely (error #4). ;)  Anything you do to avoid any of these errors will improve results.

Best,
Mark  


--- On Sun, 5/10/09, brianb at myuw.net <brianb at myuw.net> wrote:

> From: brianb at myuw.net <brianb at myuw.net>
> Subject: [ATM] myth?
> To: atm at atmlist.net
> Date: Sunday, May 10, 2009, 10:03 PM
> 
> 
> All of the books say the grid pattern on a pitch lap should
> not be centered, as zoning will occur.
> This doesn't seem right to me.
> Can this really happen?
> 
> 
> _______________________________________________
> ATM mailing list http://www.atmlist.net/
> 


      

From rsackett00 at yahoo.com  Tue May 12 20:37:26 2009
From: rsackett00 at yahoo.com (Ross Sackett)
Date: Tue, 12 May 2009 04:37:26 -0700 (PDT)
Subject: [ATM] Polisher faceting was Re:  myth?
In-Reply-To: <598596.36880.qm@web90405.mail.mud.yahoo.com>
Message-ID: <119595.92275.qm@web59206.mail.re1.yahoo.com>


Mark,

I like those polisher patterns (and that "millstone" tool!).  How do you cut those clean channels?

Ross



--- On Mon, 5/11/09, Mark Cowan <toolontop at yahoo.com> wrote:

> From: Mark Cowan <toolontop at yahoo.com>
> Subject: [ATM] Polisher faceting was Re:  myth?
> To: atm at atmlist.net
> Date: Monday, May 11, 2009, 11:52 PM
> With centered facets you're much more likely to see
> zoning as well as an imprint of the faceting pattern on the
> glass (primary ripple).  But why would this be a myth? 
> It's more like one of the 11 commandments.  
> 
> But (sacrilege!) there are better ways to facet a polisher,
> look at these: 
> 
> http://raddobs.com/atm/6inch_parab.jpg  
> http://raddobs.com/atm/nonperiodic_spin_polish_example.jpg 
> 
> 
> Good examples of the nonperiodic faceting I've used on
> all polishers for years.  Never get tool imprints with
> these!
> 
> The first is a 6" figuring tool from very soft pitch,
> tempered Gugolz 55, and the second is a 12" or so
> Acculap tool for machine polishing.  The pattern is easy to
> layout and maintain.
> 
> OTOH if you what you _want_ is zoning, be sure to use
> smaller facets (error #1), lay them out in rows with a ruler
> (error #2), all exactly the same size (error #3), and center
> the middle one precisely (error #4). ;)  Anything you do to
> avoid any of these errors will improve results.
> 
> Best,
> Mark  
> 
> 
> --- On Sun, 5/10/09, brianb at myuw.net
> <brianb at myuw.net> wrote:
> 
> > From: brianb at myuw.net <brianb at myuw.net>
> > Subject: [ATM] myth?
> > To: atm at atmlist.net
> > Date: Sunday, May 10, 2009, 10:03 PM
> > 
> > 
> > All of the books say the grid pattern on a pitch lap
> should
> > not be centered, as zoning will occur.
> > This doesn't seem right to me.
> > Can this really happen?
> > 
> > 
> > _______________________________________________
> > ATM mailing list http://www.atmlist.net/
> > 
> 
> 
>       
> _______________________________________________
> ATM mailing list http://www.atmlist.net/

From atm_ken_hunter at yahoo.com  Tue May 12 23:22:01 2009
From: atm_ken_hunter at yahoo.com (Ken Hunter)
Date: Tue, 12 May 2009 07:22:01 -0700 (PDT)
Subject: [ATM] [Fwd: Re:  Polyurethane tiles]
In-Reply-To: <4A04D0C0.1080504@gmail.com>
Message-ID: <678954.17531.qm@web52706.mail.re2.yahoo.com>


I wrote an article for Sky & Telescope about the Tile-in-Stone method in 1971 that wasn't accepted for publishing. The method has been around at least that long. I didn't invent it either...

Ken Hunter


--- On Fri, 5/8/09, Mark Holm <holmmarkd at gmail.com> wrote:

> From: Mark Holm <holmmarkd at gmail.com>
> Subject: Re: [ATM] [Fwd: Re:  Polyurethane tiles]
> To: "Michael Coslo" <mjc5 at psu.edu>
> Cc: "ATM List" <atm at atmlist.net>
> Date: Friday, May 8, 2009, 7:39 PM
> If I might defend myself a bit:
> 
> The tile-in-stone method is not very old, perhaps around a
> decade. (I certainly did not invent it.)
> 



      

From mjc5 at psu.edu  Wed May 13 00:23:42 2009
From: mjc5 at psu.edu (Michael Coslo)
Date: Tue, 12 May 2009 11:23:42 -0400
Subject: [ATM] [Fwd: Re:  Polyurethane tiles]
In-Reply-To: <4A04D0C0.1080504@gmail.com>
References: <4A038B44.6040401@gmail.com>
	<38489013-26FA-467D-B4B9-22E0244C8893@psu.edu>
	<4A04D0C0.1080504@gmail.com>
Message-ID: <53FBDEC0-E382-496C-BA32-66D9CE68C7B5@psu.edu>


On May 8, 2009, at 8:39 PM, Mark Holm wrote:

> If I might defend myself a bit:


But Mark, you don't have to defend yourself. If you or I figure out  
how to make tools from cow patties and it works, then by gosh, we  
shouldn't have to believe that we are doing something wrong.

The tool is just that - a tool. If it removes glass and doesn't  
scratch or clog up, then it's all good. Personally I like seeing  
different methods. Shows a bit of thinking. Many of those different  
methods might have a problem - but then we'd add them to the  
collective knowledge of what works and what doesn't. Just like  
science, we often learn more from our failures than our successes.

But even aside from methods that don't work, some that do work are not  
necessarily bad. While my method of plaster on wood with glued on  
tiles might not be appealing to some - it simply works, and I haven't  
had a problem with it. Took me very little time to make, cost was that  
of the epoxy - the plywood and plaster and pitch and tiles were all  
leftovers from other projects. There were no problems at all.

As soon as I see some evidence that a mirror made with a Hydrostone or  
dental stone tool is better than one made with anything else, I'll be  
the first to say it's "This is what you should use". But until then,  
I'll say that there is more than one way to grind a mirror, and more  
than one way to make a tool. I'd have no hesitation to give a noob a  
choice between my type tool and the "proper" tool. Both will work just  
fine.

So your tool making method is good. But so is mine, and we're all  
about making telescopes in the end. If we get too hung up on tool  
making styles, we can sound like we're down at the corner gas, arguing  
about Ferds' and Chivvys... 8^)


-73 de Mike N3LI -



From mjc5 at psu.edu  Wed May 13 00:44:59 2009
From: mjc5 at psu.edu (Michael Coslo)
Date: Tue, 12 May 2009 11:44:59 -0400
Subject: [ATM] [Fwd: Re:  Polyurethane tiles]
In-Reply-To: <000f01c9d0fb$f1c8b0c0$8f78fea9@amd>
References: <4A038B44.6040401@gmail.com> <C248E9F6FACC4A7188C1437A70885CE1@tom>
	<DA1A8CCD-569F-461D-92B5-C9680ACD09D9@psu.edu>
	<B7205FD67ECD4599947682DC15FC81D8@tom>
	<000f01c9d0fb$f1c8b0c0$8f78fea9@amd>
Message-ID: <24561C57-D139-4271-A4A2-1B34A13EA6C9@psu.edu>


On May 9, 2009, at 7:14 PM, Bob May wrote:

> IF YOU USE THE TILE TOOL TO DO THE INITIAL CARVING, YOU WILL FIND
> IT BETTER TO DO THE TILES ON EDGE!!!

I may have asked this question before, but are you using clay tiles? I  
use porcelain tiles, and they generate the curve at the same rate as  
the mirror. I do know some folks have used clay tiles, and wore their  
tools down pretty quickly. I wouldn't recommend clay.

I've used iron tools and they work well, but something is a little  
disconnected here. My tile tools go the whole way from hogging to fine  
grinding, and don't have any wear that the mirror doesn't have.

Maybe that is the issue - My tools don't need the seating in that the  
cast tiles need, and we could be arguing past each other. But  
seriously, making one tool from start to finish is a labor saver, IMO.  
I'll be taking up this cast tool thing in another thread here soon.

-73 de Mike N3LI -



From mjc5 at psu.edu  Wed May 13 00:56:09 2009
From: mjc5 at psu.edu (Michael Coslo)
Date: Tue, 12 May 2009 11:56:09 -0400
Subject: [ATM] [Fwd: Re:  Polyurethane tiles]
In-Reply-To: <000601c9d1b7$03edb460$8f78fea9@amd>
References: <4A069FDF.1070406@mweb.co.za> <000601c9d1b7$03edb460$8f78fea9@amd>
Message-ID: <D6B17F02-CC77-492A-BFE8-6441DDFA25F2@psu.edu>


On May 10, 2009, at 5:33 PM, Bob May wrote:

> One thing that I'm having trouble understanding is why there
> needs to be channels on the tool???

My original mirror, I used a glass tool. It was another blank. I used  
it because the original  owner started the mirror with it, and I  
didn't know much better.

The solid tool has a tendency to stick to the blank occasionally, and  
can be a real issue to get them unstuck. Scary things like rubber  
mallets, and other semi brutal methods. Sometimes what works best is  
to stick the whole shebang in a bathtub for a couple days. A true PITA.

I haven't had it happen since going to  channeled tools. The process  
of the problem might be part capillary action, maybe some surface  
tension. I also suspect that the better the alignment, that is the  
mirror and tool being an exact fit, might make the problem more  
likely. Certainly the channeled tools will never match exactly.

-73 de Mike N3LI -



From mjc5 at psu.edu  Wed May 13 00:57:42 2009
From: mjc5 at psu.edu (Michael Coslo)
Date: Tue, 12 May 2009 11:57:42 -0400
Subject: [ATM] Polyurethane tiles Shirt color
In-Reply-To: <A1300F766A0B41759AEF1003A40916AC@HELENYLCMWAV95>
References: <20090510.164341.2896.0.jkoptic@juno.com>
	<A1300F766A0B41759AEF1003A40916AC@HELENYLCMWAV95>
Message-ID: <3E342F74-4E8A-4E55-A9C6-DFA1EA9CE016@psu.edu>


On May 10, 2009, at 8:25 PM, Francis J. O'Reilly wrote:
>
> I am somewhat amazed by the amount of discussion spent on such  
> matters, more grinding and less writing about it would probably be  
> most effective, just as it was in 1947.


You are right, of course.

-73 de Mike N3LI -



From richard at foucault.co.uk  Wed May 13 01:18:17 2009
From: richard at foucault.co.uk (Richard in the UK)
Date: Tue, 12 May 2009 17:18:17 +0100
Subject: [ATM] [Fwd: Re:  Polyurethane tiles]
In-Reply-To: <D6B17F02-CC77-492A-BFE8-6441DDFA25F2@psu.edu>
References: <4A069FDF.1070406@mweb.co.za> <000601c9d1b7$03edb460$8f78fea9@amd>
	<D6B17F02-CC77-492A-BFE8-6441DDFA25F2@psu.edu>
Message-ID: <21444411.20090512171817@foucault.co.uk>

Hello Michael,

Tuesday, May 12, 2009, 4:56:09 PM, you wrote:

> I haven't had it happen since going to  channeled tools. The process  
> of the problem might be part capillary action, maybe some surface  
> tension.

I'm pretty sure it's contact adhesion. As soon as the surface are in
intimate enough contact to exclude air from getting in, then you have
14.7 PSI pressing on both sides. Half a ton for a 10" !.

-- 
Best regards,
 Richard in the UK


From foreilly at bestweb.net  Wed May 13 01:21:58 2009
From: foreilly at bestweb.net (Francis J. O'Reilly)
Date: Tue, 12 May 2009 12:21:58 -0400
Subject: [ATM] Polyurethane tiles Shirt color
References: <20090510.164341.2896.0.jkoptic@juno.com>
	<A1300F766A0B41759AEF1003A40916AC@HELENYLCMWAV95>
	<3E342F74-4E8A-4E55-A9C6-DFA1EA9CE016@psu.edu>
Message-ID: <9518FB87B74A440789AC6D51CD62258A@D5GHLR11>

Sorry for being a wise guy, I get that way sometimes and push the send
button for too quickly.

Francis J. O'Reilly
----- Original Message ----- 
From: "Michael Coslo" <mjc5 at psu.edu>
To: "ATM List" <atm at atmlist.net>
Sent: Tuesday, May 12, 2009 11:57 AM
Subject: Re: [ATM] Polyurethane tiles Shirt color


>
> On May 10, 2009, at 8:25 PM, Francis J. O'Reilly wrote:
>>
>> I am somewhat amazed by the amount of discussion spent on such  matters,
>> more grinding and less writing about it would probably be  most
>> effective, just as it was in 1947.
>
>
> You are right, of course.
>
> -73 de Mike N3LI -
>
>
> _______________________________________________
> ATM mailing list http://www.atmlist.net/


From mjc5 at psu.edu  Wed May 13 01:58:19 2009
From: mjc5 at psu.edu (Michael Coslo)
Date: Tue, 12 May 2009 12:58:19 -0400
Subject: [ATM] [Fwd: Re:  Polyurethane tiles]
In-Reply-To: <4A077C3C.4020506@outofoptions.org>
References: <4A069FDF.1070406@mweb.co.za> <000601c9d1b7$03edb460$8f78fea9@amd>
	<CD74BA23C5FA4AC78DABD64B4E743BA2@tom>
	<4A077C3C.4020506@outofoptions.org>
Message-ID: <A7B5A5D2-9378-45E5-8E89-415B2662E359@psu.edu>


On May 10, 2009, at 9:15 PM, hermit wrote:

> Tom Stokes wrote:
>> I also don't understand why Mel Bartels uses only micro faceting on  
>> his laps. Perhaps you "old guys" are coming up with something new.
>>
>> Tom Stokes
>>
> I think it leads to less micro ripple if I remember correctly.  The  
> way I make my laps though, I need the channels to get the mirror and  
> lap into good contact.  After that, micro channels are enough to  
> hold moisture and polish to prolong the 'wet'.


Same here, I tried a microfacet only lap, and discovered I would have  
to pre-generate a curve in it, so I channeled, and let them close up.  
I believe that Mel uses a method that sort of humps up the pitch in  
the middle. Ends up the same in either case.


-73 de Mike N3LI -



From mjc5 at psu.edu  Wed May 13 02:02:42 2009
From: mjc5 at psu.edu (Michael Coslo)
Date: Tue, 12 May 2009 13:02:42 -0400
Subject: [ATM] [Fwd: Re:  Polyurethane tiles]
In-Reply-To: <Pine.LNX.4.44.0905110954040.28033-100000@uno.canit.se>
References: <Pine.LNX.4.44.0905110954040.28033-100000@uno.canit.se>
Message-ID: <C89B6E6A-F156-445A-8042-DB026D617009@psu.edu>


On May 11, 2009, at 3:57 AM, Dominic-Luc Webb wrote:

> On Fri, 8 May 2009, Michael Coslo wrote:
>> Are you using porcelain tiles? they should last as long as the glass
>> does.
>
>
> I'm not so sure. My tiles behave less hard than glass and,
> because they are tiles, they have less total area than the
> mirror. I would expect one way or other tile thickness is
> lost faster than mirror thickness.


There are some type of porcelain tiles that are even harder - they  
tend to have color right in the tile. Mine were a solid gray color -  
called ColorBody IIRC. These things were really hard, and perhaps that  
helped some.


-73 de Mike N3LI -



From stainless_steel at suddenlink.net  Wed May 13 02:07:15 2009
From: stainless_steel at suddenlink.net (stainless_steel at suddenlink.net)
Date: Tue, 12 May 2009 12:07:15 -0500
Subject: [ATM] ATM:ATM: reply, forward Re: Polyurethane tiles
Message-ID: <E0048BC4F79D47FDA7B508F2C0F88464@R101>

Bob-

Make the channels only (and keep them this way) two thirty seconds 
(2/32ndths) of an inch deep, by waxing the tool as per my article, and you 
will decide that what you wrote below can only be true for a tool that has 
no wax in the channels.

You see, when I made my first channelled tile tool, I did not have any idea 
how to keep the grit from running away down through the deep channels- and 
yes, it ran out quickly when mirror was on top. That is the PRIMARY reason I 
came up with the waxing idea. I asure you that the grit will stay in place- 
I mean, as the grit becomes spent, only a little bit escapes from the tool, 
even if you are starting with coarse carborundum.

After your tiles come to curve, wet the back of the mirror, and watch the 
very strange appearing action: with all the strokes there will be a grey, 
"amoeba" like creature, on each tile, surging back and forth in almost 
identical fashion- just keep the was between the tiles excavated down to 
about 2/32ths of an inch in depth- as you grind, the tiles will come down to 
the level of the wax, and you will have to take a break, and use a little 
screwdriver (very little) and scrape a tiny amount of the wax out between 
the tiles. You have the best of both worlds; the tile tool will behave as a 
monolithic tool in terms of grit economy, and any "rogue grit" will get 
trapped in the wax, if that accident happens.

Try a tool with very shallow channels- you will turn your back on monolithic 
grinding tools-

Be well, Bob, all-

DLZ-130

P.S.- With my first mirror, a Willman Bell kit, the eight inch blank and 
matching monolithic tool seized during fine grinding; also got my only huge 
gouge too. My second mirror was a 12.5" with an all ceramic tool, large 
Terra Cotta floor tiles nipped round and laminated, together, and put hexes 
on its face, and left them about the width of a kitchen matchstick apart. 
Immediaztely I started hogging out, the grit ran away into the abyss. I 
promply waxed those little linear spaces in between tiiles, and presto: NO 
MORE "DISAPPEARING GRIT" with the mirror on top. Works like a dream. One or 
two of the list members have tried this and it works unbelievably well.

Some one came to Enid and bought the full thickness Corning 16" blank and 
two featured here (I think it was Ron Gafron)- and the others who've tried 
it and done the waxing as per the article, have not complained about losing 
grit. That's what the waxing of the channels is for, and it works well. Why 
did I not explain that in the article? Maybe I did. I think I will go back 
and read it again.

http://www.atmsite.org/contrib/Harbour/Tool.html


>Ken, I have looked through the glass and looked at the grit/glass
>that gets washed off of the tool afterwords.  Everything that
>starts out in a groove stays there.  Much of what is on the tiles
>falls down after a roll or two.  Unused grit that gets recovered
>from the wash water ends up being on the order of 90% or more
>whereas a solid tool produces about 10% unused grit.  Not all
>that good on using the grit when channeled tools are used.
>The Newport "channeling" doesn't help with the vacuum problem all
>that much as there is no point where the channel gets to the
>outside of the tool.  Fill the channel with water and you get a
>nice lock.  I occasionally do channel a tile tool but that is
>just a scratch from the center to the edge of the tool, just for
>an air passage rather than a deep channel for holding grit.
>Bob May

rmay at nethere.com
http: slash /nav.to slash bobmay
http: slash /bobmay dot astronomy.net


From mjc5 at psu.edu  Wed May 13 02:07:44 2009
From: mjc5 at psu.edu (Michael Coslo)
Date: Tue, 12 May 2009 13:07:44 -0400
Subject: [ATM] myth?
In-Reply-To: <491798bed2ef1177773b8da404b72124@verizon.net>
References: <Pine.LNX.4.43.0905102203400.20647@hur12.myuw.net>
	<491798bed2ef1177773b8da404b72124@verizon.net>
Message-ID: <010ACA46-CADA-4B00-A1E0-D8C641C2AAAF@psu.edu>


On May 11, 2009, at 7:14 AM, don surles wrote:
>
>
> BTW...I have never repeated the centered pitch lap pattern.

If a person was really really bad, it might not happen. Of course  
there would be lots of other problems.. 8^)


> -73 de Mike N3LI -




From stainless_steel at suddenlink.net  Wed May 13 02:16:46 2009
From: stainless_steel at suddenlink.net (stainless_steel at suddenlink.net)
Date: Tue, 12 May 2009 12:16:46 -0500
Subject: [ATM] ATM: I repeat myself about channelling-
Message-ID: <0237BE9B645C4F7B82ACA27477D09AA8@R101>

Bob-

Make the channels only (and keep them this way) two thirty seconds
(2/32ndths) of an inch deep, by waxing the tool as per my article, and you
will decide that what you wrote below can only be true for a tool that has
no wax in the channels.

You see, when I made my first channelled tile tool, I did not have any idea
how to keep the grit from running away down through the deep channels- and
yes, it ran out quickly when mirror was on top. That is the PRIMARY reason I
came up with the waxing idea. I asure you that the grit will stay in place-
I mean, as the grit becomes spent, only a little bit escapes from the tool,
even if you are starting with coarse carborundum.

After your tiles come to curve, wet the back of the mirror, and watch the
very strange appearing action: with all the strokes there will be a grey,
"amoeba" like creature, on each tile, surging back and forth in almost
identical fashion- just keep the was between the tiles excavated down to
about 2/32ths of an inch in depth- as you grind, the tiles will come down to
the level of the wax, and you will have to take a break, and use a little
screwdriver (very little) and scrape a tiny amount of the wax out between
the tiles. You have the best of both worlds; the tile tool will behave as a
monolithic tool in terms of grit economy, and any "rogue grit" will get
trapped in the wax, if that accident happens.

Try a tool with very shallow channels- you will turn your back on monolithic
grinding tools-

Be well, Bob, all-

DLZ-130

P.S.- With my first mirror, a Willman Bell kit, the eight inch blank and
matching monolithic tool seized during fine grinding; also got my only huge
gouge too. My second mirror was a 12.5" with an all ceramic tool, large
Terra Cotta floor tiles nipped round and laminated, together, and put hexes
on its face, and left them about the width of a kitchen matchstick apart.
Immediaztely I started hogging out, the grit ran away into the abyss. I
promply waxed those little linear spaces in between tiiles, and presto: NO
MORE "DISAPPEARING GRIT" with the mirror on top. Works like a dream. One or
two of the list members have tried this and it works unbelievably well.

Some one came to Enid and bought the full thickness Corning 16" blank and
two featured here (I think it was Ron Gafron)- and the others who've tried
it and done the waxing as per the article, have not complained about losing
grit. That's what the waxing of the channels is for, and it works well. Why
did I not explain that in the article? Maybe I did. I think I will go back
and read it again.

http://www.atmsite.org/contrib/Harbour/Tool.html


>Ken, I have looked through the glass and looked at the grit/glass
>that gets washed off of the tool afterwords.  Everything that
>starts out in a groove stays there.  Much of what is on the tiles
>falls down after a roll or two.  Unused grit that gets recovered
>from the wash water ends up being on the order of 90% or more
>whereas a solid tool produces about 10% unused grit.  Not all
>that good on using the grit when channeled tools are used.
>The Newport "channeling" doesn't help with the vacuum problem all
>that much as there is no point where the channel gets to the
>outside of the tool.  Fill the channel with water and you get a
>nice lock.  I occasionally do channel a tile tool but that is
>just a scratch from the center to the edge of the tool, just for
>an air passage rather than a deep channel for holding grit.
>Bob May

rmay at nethere.com
http: slash /nav.to slash bobmay
http: slash /bobmay dot astronomy.net


>>Channeling is another problem with doing tiles in the tool.  As
>>you channel, you often want to make sure you have Grand Canyons
>>of channels so you weaken the stone by removing most of the stone
>>from the sides of the tiles and thus, the tiles can then break
>>off the little bit left and next thing you know is that there is
>>no tile where it belongs!  Even a matted tile will break loose if
>>you channel a lot.  The whole retaining of the tile in the tool
>>is mechanical clamping and not actual "gluing" of the two
>>surfaces together.
>>Bob May

rmay at nethere.com
http: slash /nav.to slash bobmay
http: slash /bobmay dot astronomy.net


From stainless_steel at suddenlink.net  Wed May 13 02:25:09 2009
From: stainless_steel at suddenlink.net (stainless_steel at suddenlink.net)
Date: Tue, 12 May 2009 12:25:09 -0500
Subject: [ATM] ATM: Channeled grinding tools-
Message-ID: <6F6564AEA1A44902B7B17B60EFBFD3F3@R101>

Michael,

By the time you are in the finer grades of alox, with no pits left over from 
the larger carbo, and you do the pencil test on each tile, you will see that 
a tile tool does in fact, in the end, fit precisely, everywhere. If it 
didn't, making a successfull mirror with a channeled tool would be 
impossible.

DLZ-130


On May 10, 2009, at 5:33 PM, Bob May wrote:

> One thing that I'm having trouble understanding is why there
> needs to be channels on the tool???

My original mirror, I used a glass tool. It was another blank. I used
it because the original  owner started the mirror with it, and I
didn't know much better.

The solid tool has a tendency to stick to the blank occasionally, and
can be a real issue to get them unstuck. Scary things like rubber
mallets, and other semi brutal methods. Sometimes what works best is
to stick the whole shebang in a bathtub for a couple days. A true PITA.

I haven't had it happen since going to  channeled tools. The process
of the problem might be part capillary action, maybe some surface
tension. I also suspect that the better the alignment, that is the
mirror and tool being an exact fit, might make the problem more
likely. Certainly the channeled tools will never match exactly.

-73 de Mike N3LI -


From stainless_steel at suddenlink.net  Wed May 13 02:32:28 2009
From: stainless_steel at suddenlink.net (stainless_steel at suddenlink.net)
Date: Tue, 12 May 2009 12:32:28 -0500
Subject: [ATM] ATM: Polishing tools, not grinding tools!
Message-ID: <33C1F9E0BAC1439992432A5329F58166@R101>

I see now that the emphasis is on the channels in polishing tools.

They are there for a different reason than channels in grinding tools. They 
allow the pitch to expand, allowing the lap to match the mirror's changing 
curve expeditiously. And, in that case, when one is figuring, it has to be 
true that the pitch lap does not fit the curve on the mirror precisely; but 
pressing allows it to "follow" the developing figure on the mirror.

I worked the inbox que from the bottom up, as usual, and didn't get that the 
thread was about channels in polishing tools, until just now. Not a rocket 
scientist. Perhaps I will start working the list in the other direction-

DLZ-130 


From tom_krajci at tularosa.net  Wed May 13 02:52:52 2009
From: tom_krajci at tularosa.net (Tom Krajci)
Date: Tue, 12 May 2009 11:52:52 -0600
Subject: [ATM] Another source of heat rope
In-Reply-To: <mailman.846.1242148616.7676.atm@atmlist.net>
References: <mailman.846.1242148616.7676.atm@atmlist.net>
Message-ID: <4A09B774.6070302@tularosa.net>

I've found another source of heat rope:
http://www.pelicanwire.com/onlinestore.htm

I recommend you use Nichrome 60, about 29 gauge, with fiberglass 
insulation/jacket.  A 50-foot spool is $30 plus shipping.  That's a 
lifetime supply...or a good buy for a club.

29-gauge nichrome 60 is about 5 ohms per foot.
http://www.pelicanwire.com/alloyproperties.htm#n60

-- 
-------------------------------------------
Tom Krajci
Cloudcroft, New Mexico
http://picasaweb.google.com/tom.krajci

Center for Backyard Astrophysics (CBA)
http://cbastro.org/ CBA New Mexico

American Association of Variable Star
Observers (AAVSO): KTC http://www.aavso.org/
-------------------------------------------



From don.surles at verizon.net  Wed May 13 03:10:54 2009
From: don.surles at verizon.net (don surles)
Date: Tue, 12 May 2009 14:10:54 -0400
Subject: [ATM] [Fwd: Re:  Polyurethane tiles]
In-Reply-To: <D6B17F02-CC77-492A-BFE8-6441DDFA25F2@psu.edu>
References: <4A069FDF.1070406@mweb.co.za> <000601c9d1b7$03edb460$8f78fea9@amd>
	<D6B17F02-CC77-492A-BFE8-6441DDFA25F2@psu.edu>
Message-ID: <8d5f27565a44d0bf55787495fe184d9f@verizon.net>

sticking mirrors and tools...i have always used a smooth glass tool, 
and in the beginning I experienced sticking and actually had my first 
stuck mirror damaged when it broke loose in the kitchen sink.

I believe in OTJ learning and I earned quite a bit from all those 
errors of early mirror making:

1) stop grinding before the "stick";  keep the grit fresh!
2) if there is a "stick" then the breaking apart needs to be done on a 
carpeted floor sos'n there is no chance for gravity to break a mirror 
or tool that unexpectedly goes airborne
3) learn from your mistakes and learn from the success of 
others...imitation is ????flattery?

grind more and worry less.

Don...



On May 12, 2009, at 11:56 AM, Michael Coslo wrote:

>
> On May 10, 2009, at 5:33 PM, Bob May wrote:
>
>> One thing that I'm having trouble understanding is why there
>> needs to be channels on the tool???
>
> My original mirror, I used a glass tool. It was another blank. I used 
> it because the original  owner started the mirror with it, and I 
> didn't know much better.
>
> The solid tool has a tendency to stick to the blank occasionally, and 
> can be a real issue to get them unstuck. Scary things like rubber 
> mallets, and other semi brutal methods. Sometimes what works best is 
> to stick the whole shebang in a bathtub for a couple days. A true 
> PITA.
>
> I haven't had it happen since going to  channeled tools. The process 
> of the problem might be part capillary action, maybe some surface 
> tension. I also suspect that the better the alignment, that is the 
> mirror and tool being an exact fit, might make the problem more 
> likely. Certainly the channeled tools will never match exactly.
>
> -73 de Mike N3LI -
>
>
> _______________________________________________
> ATM mailing list http://www.atmlist.net/
>
>
Don Surles


From don.surles at verizon.net  Wed May 13 03:12:44 2009
From: don.surles at verizon.net (don surles)
Date: Tue, 12 May 2009 14:12:44 -0400
Subject: [ATM] [Fwd: Re:  Polyurethane tiles]
In-Reply-To: <21444411.20090512171817@foucault.co.uk>
References: <4A069FDF.1070406@mweb.co.za> <000601c9d1b7$03edb460$8f78fea9@amd>
	<D6B17F02-CC77-492A-BFE8-6441DDFA25F2@psu.edu>
	<21444411.20090512171817@foucault.co.uk>
Message-ID: <abc23d27893b7bb37c922e14a70625c1@verizon.net>

keep the grit fresh and avoid sticking.

Don...


On May 12, 2009, at 12:18 PM, Richard in the UK wrote:

> Hello Michael,
>
> Tuesday, May 12, 2009, 4:56:09 PM, you wrote:
>
>> I haven't had it happen since going to  channeled tools. The process
>> of the problem might be part capillary action, maybe some surface
>> tension.
>
> I'm pretty sure it's contact adhesion. As soon as the surface are in
> intimate enough contact to exclude air from getting in, then you have
> 14.7 PSI pressing on both sides. Half a ton for a 10" !.
>
> -- 
> Best regards,
>  Richard in the UK
>
> _______________________________________________
> ATM mailing list http://www.atmlist.net/
>
>
Don Surles


From hermit at outofoptions.org  Wed May 13 03:17:14 2009
From: hermit at outofoptions.org (hermit)
Date: Tue, 12 May 2009 14:17:14 -0400
Subject: [ATM] Another source of heat rope
In-Reply-To: <4A09B774.6070302@tularosa.net>
References: <mailman.846.1242148616.7676.atm@atmlist.net>
	<4A09B774.6070302@tularosa.net>
Message-ID: <4A09BD2A.1040105@outofoptions.org>

Tom Krajci wrote:
> I've found another source of heat rope:
> http://www.pelicanwire.com/onlinestore.htm
>
> I recommend you use Nichrome 60, about 29 gauge, with fiberglass 
> insulation/jacket.  A 50-foot spool is $30 plus shipping.  That's a 
> lifetime supply...or a good buy for a club.
>
> 29-gauge nichrome 60 is about 5 ohms per foot.
> http://www.pelicanwire.com/alloyproperties.htm#n60

time for gotheatrope.com ? :D

Ken Lowther


From hermit at outofoptions.org  Wed May 13 03:18:41 2009
From: hermit at outofoptions.org (hermit)
Date: Tue, 12 May 2009 14:18:41 -0400
Subject: [ATM] [Fwd: Re:  Polyurethane tiles]
In-Reply-To: <abc23d27893b7bb37c922e14a70625c1@verizon.net>
References: <4A069FDF.1070406@mweb.co.za>
	<000601c9d1b7$03edb460$8f78fea9@amd>	<D6B17F02-CC77-492A-BFE8-6441DDFA25F2@psu.edu>	<21444411.20090512171817@foucault.co.uk>
	<abc23d27893b7bb37c922e14a70625c1@verizon.net>
Message-ID: <4A09BD81.6010602@outofoptions.org>

don surles wrote:
> keep the grit fresh and avoid sticking.
>
> Don...
>
>
Sticking at least once is a rite of passage isn't it?

Ken Lowther

From vorblesnak at peak.org  Wed May 13 03:29:16 2009
From: vorblesnak at peak.org (vorblesnak at peak.org)
Date: Tue, 12 May 2009 11:29:16 -0700 (PDT)
Subject: [ATM] Glass foam mirrors pushing the envelope
Message-ID: <3097.69.59.200.230.1242152956.squirrel@webmail.peak.org>

I thought I should post and address some of the questions and comments ..

There was a patent on a similar process filed in Sweden?? back in the
early 80's. That patent has been allowed to expire so I suspect the value
was questioned; or something.

Today I read on the Alt Az initiative group over on Yahoo that the Air
Force was using glass foam mirrors in 1957 or there abouts. From that post
...

> > I was looking around for information about aerial camera lenses used in
> > spy planes (probably good for astrophotography), and found an
> > interesting passage in a book called "Spyplane" by Norman Polmar.  The
> > passage reads:
> >
> > "Later in the year (1955) Baker tried making the mirrors for the system
> > out of a new, lightweight foamed silica material developed by the
> > Pittsburg-Corning Glass Company.  This reduced the weight significantly,
> > and he was scale up the lens to a 180" f/13.85 reflective system for a
> > 13" by 13" format.  ...   When a C camera was built by Hycon was flight
> > tested on 31 January 1957 ..."
> >
> >    So, people were successfully making foam glass mirrors as far back in
> > 1957!  Since these cameras were designed for spy planes, the image
> > quality should have been excellent.  Has the knowledge of how to make
> > foamglass mirrors been lost, or just classified?
> >
> > Cheers
> > Mike Connelley

My purpose for the work is to find a backer for ultrathin glass. The goal
being to make light ponds, (as opposed to light buckets), for amateur
telescopes. Light weight is just an unforeseen benefit. Size and cost
being the main motivations. A 1.5 meter disk can be had for about $500 or
less delivered. The foam to back it runs about $200 more. Depending on
design that works out to less than $1000 for a 1.5 meter mirror.

I had a no guilt chance to try and slump a 1.5 meter disk that would have
been mounted on glass foam for working. I screwed up the process and
shattered the blank. Ah well, broke another one. I still have my 48 inch
and my 42's and a better understanding of the process. But even at
ultrathin sizes, 0.5" inches thick on the 1.5 meter disk, the glass was
too large for one person to handle. I am looking at Richey's grinding
machine designs to handle the really big glass.

I want to thank all the volunteers who took a blank to make a mirror. I
hope they work out and that the figure holds true.

Should be fun to watch over the next few weeks.

David Davis
Toledo, OR 97391


>Is there already a patent on this process?  Just wondering if
>commercial motivations are protected by a patent already...  Check out
>the link below:

>http://www.freepatentsonline.com/4670338.html

>Shane

>On May 11, 2009, at 8:32 PM, Russell Jocoy wrote:

>   To all on the list, I would like to congradulate David Davis for
> his continueing drive to push the envelope. His new idea is still
> unfound, and could turn out to be unaceptable as a lightwieght






From wa4guu at verizon.net  Wed May 13 04:19:55 2009
From: wa4guu at verizon.net (Jerry)
Date: Tue, 12 May 2009 15:19:55 -0400
Subject: [ATM] [Fwd: Re:  Polyurethane tiles]
In-Reply-To: <4A09BD81.6010602@outofoptions.org>
Message-ID: <91729D78B6B643F6BB2A2F85FC6C8374@D85SJB21>

This is when I should tell the story about using the car jack
(click-click... click-click... click-click...) to separate two 12.5" Pyrex
blanks. They were cheap then or at least I had more than I needed. And who
knows? Maybe I would need a 12.5" secondary for a Cassegrain some day and
have a head start on the curve. 

But I've probably already told this one before.

Jerry



-----Original Message-----
From: atm-bounces at atmlist.net [mailto:atm-bounces at atmlist.net] On Behalf Of
hermit
Sent: Tuesday, May 12, 2009 2:19 PM
Cc: Michael Coslo
Subject: Re: [ATM] [Fwd: Re: Polyurethane tiles]

don surles wrote:
> keep the grit fresh and avoid sticking.
>
> Don...
>
>
Sticking at least once is a rite of passage isn't it?

Ken Lowther
_______________________________________________
ATM mailing list http://www.atmlist.net/


From toolontop at yahoo.com  Wed May 13 05:09:30 2009
From: toolontop at yahoo.com (Mark Cowan)
Date: Tue, 12 May 2009 13:09:30 -0700 (PDT)
Subject: [ATM] Polisher faceting was Re:  myth?
Message-ID: <364995.53353.qm@web90406.mail.mud.yahoo.com>



I use a 4 inch plastic window scraper with ordinary steel and a small hammer, just a couple strokes on each side of the channel-to-be under running water.  Goes quite fast that way.

BTW I looked for stainless blades for this and could never find any.  But what with pitch residue and the like the amount of rust that builds up never seems to be a problem, as I'm still on the original blade.  It doesn't have to be terribly sharp.

Best,
Mark

--- On Tue, 5/12/09, Ross Sackett <rsackett00 at yahoo.com> wrote:

> From: Ross Sackett <rsackett00 at yahoo.com>
> Subject: Re: [ATM] Polisher faceting was Re:  myth?
> To: atm at atmlist.net, "Mark Cowan" <toolontop at yahoo.com>
> Date: Tuesday, May 12, 2009, 4:37 AM
> 
> Mark,
> 
> I like those polisher patterns (and that "millstone"
> tool!).? How do you cut those clean channels?
> 
> Ross
> 
> 
> 
> --- On Mon, 5/11/09, Mark Cowan <toolontop at yahoo.com>
> wrote:
> 
> > From: Mark Cowan <toolontop at yahoo.com>
> > Subject: [ATM] Polisher faceting was Re:? myth?
> > To: atm at atmlist.net
> > Date: Monday, May 11, 2009, 11:52 PM
> > With centered facets you're much more likely to see
> > zoning as well as an imprint of the faceting pattern
> on the
> > glass (primary ripple).? But why would this be a
> myth? 
> > It's more like one of the 11 commandments.? 
> > 
> > But (sacrilege!) there are better ways to facet a
> polisher,
> > look at these: 
> > 
> > http://raddobs.com/atm/6inch_parab.jpg? 
> > http://raddobs.com/atm/nonperiodic_spin_polish_example.jpg
> 
> > 
> > 
> > Good examples of the nonperiodic faceting I've used
> on
> > all polishers for years.? Never get tool imprints
> with
> > these!
> > 
> > The first is a 6" figuring tool from very soft pitch,
> > tempered Gugolz 55, and the second is a 12" or so
> > Acculap tool for machine polishing.? The pattern
> is easy to
> > layout and maintain.
> > 
> > OTOH if you what you _want_ is zoning, be sure to use
> > smaller facets (error #1), lay them out in rows with a
> ruler
> > (error #2), all exactly the same size (error #3), and
> center
> > the middle one precisely (error #4). ;)? Anything
> you do to
> > avoid any of these errors will improve results.
> > 
> > Best,
> > Mark? 
> > 
> > 
> > --- On Sun, 5/10/09, brianb at myuw.net
> > <brianb at myuw.net>
> wrote:
> > 
> > > From: brianb at myuw.net
> <brianb at myuw.net>
> > > Subject: [ATM] myth?
> > > To: atm at atmlist.net
> > > Date: Sunday, May 10, 2009, 10:03 PM
> > > 
> > > 
> > > All of the books say the grid pattern on a pitch
> lap
> > should
> > > not be centered, as zoning will occur.
> > > This doesn't seem right to me.
> > > Can this really happen?
> > > 
> > > 
> > > _______________________________________________
> > > ATM mailing list http://www.atmlist.net/
> > > 
> > 
> > 
> >? ? ???
> > _______________________________________________
> > ATM mailing list http://www.atmlist.net/
> 


      

From rmay at nethere.com  Wed May 13 05:30:34 2009
From: rmay at nethere.com (Bob May)
Date: Tue, 12 May 2009 13:30:34 -0700
Subject: [ATM] ATM: I repeat myself about channelling-
References: <0237BE9B645C4F7B82ACA27477D09AA8@R101>
Message-ID: <002901c9d340$829d89e0$8f78fea9@amd>

Yep, small channels if you want them.  Problem is that most seem
to think that bigger is better here and thus they go and cut all
of the support from the tiles and they then come loose.  In
addition, I don't really like the idea of vertical surfaces in
contact with the mirror.  The probablity of them spalling off a
clamshell just seems too great for me to consider.
Bob May

rmay at nethere.com
http: slash /nav.to slash bobmay
http: slash /bobmay dot astronomy.net



From rmay at nethere.com  Wed May 13 05:37:28 2009
From: rmay at nethere.com (Bob May)
Date: Tue, 12 May 2009 13:37:28 -0700
Subject: [ATM] [Fwd: Re:  Polyurethane tiles]
References: <4A038B44.6040401@gmail.com>
	<C248E9F6FACC4A7188C1437A70885CE1@tom><DA1A8CCD-569F-461D-92B5-C9680ACD09D9@psu.edu><B7205FD67ECD4599947682DC15FC81D8@tom><000f01c9d0fb$f1c8b0c0$8f78fea9@amd>
	<24561C57-D139-4271-A4A2-1B34A13EA6C9@psu.edu>
Message-ID: <004101c9d342$f3e8eac0$8f78fea9@amd>

For long focal length small (12" and under) mirrors, just casting
a tile tool with the original flat surface will work.  HOWEVER,
with fast and large mirrors, there isn't enough tile thickness to
do the job.  Also, some blanks don't have a flat surface to
begine with so you will be spending a lot of time just getting it
to the flat condition from some convex shape and that will make
things worse.
As to using iron tools to shape the surface first to a rough
sphere, you can be a long way from being spherical if you cast
the tool after the hole is dug.  You can easily do a very steep
curve and only approximate a sphere and still be able to do the
matching without needing a second set of surface on the tool to
get the job done.
Bob May

rmay at nethere.com
http: slash /nav.to slash bobmay
http: slash /bobmay dot astronomy.net



From rmay at nethere.com  Wed May 13 05:48:05 2009
From: rmay at nethere.com (Bob May)
Date: Tue, 12 May 2009 13:48:05 -0700
Subject: [ATM] [Fwd: Re:  Polyurethane tiles]
References: <4A069FDF.1070406@mweb.co.za> <000601c9d1b7$03edb460$8f78fea9@amd>
	<D6B17F02-CC77-492A-BFE8-6441DDFA25F2@psu.edu>
Message-ID: <004201c9d342$f4aab420$8f78fea9@amd>

When you watch what you're doing as to water on the tool as well
as doing a proper grinding procedure (no long strokes) the
probability of having a lock becomes extremelly slim.
Strokes too long make the mirror hyperboloid and thus you have a
hole in the center where the vacuum gets generated.  Cure is to
do short strokes near the COC stroke until you get the hole out.
Running a wet too long gets the grit too small to keep the mirror
rolling over the tool and thus the sphericalization that
gradually is (the large grit does a bad hyperbola and as you go
down through the grits, that hyperboloid gradually gets smaller)
being done becomes larger than the grit and you get a lock.  In
addition, the glass trash tends to bind to something in hte water
and you get a weak glue that way.
Not enough water also becomes a problem as the glass and grit
tend to glue to each other a lot faster.
Small scratches will allow air into the central area of the
surface without any problems.  Needless to say, the bigger the
path, the easier it is to get the air into the central area of
the mirror.
Bob May

rmay at nethere.com
http: slash /nav.to slash bobmay
http: slash /bobmay dot astronomy.net



From rmay at nethere.com  Wed May 13 05:56:28 2009
From: rmay at nethere.com (Bob May)
Date: Tue, 12 May 2009 13:56:28 -0700
Subject: [ATM] [Fwd: Re:  Polyurethane tiles]
References: <Pine.LNX.4.44.0905110954040.28033-100000@uno.canit.se>
	<C89B6E6A-F156-445A-8042-DB026D617009@psu.edu>
Message-ID: <004f01c9d344$3848c5e0$8f78fea9@amd>

Please understand that there are two types of tiles sold for
houses, etc.
There is the wall tile.  This is a soft tile with a coating on
the one surface so that it looks pretty.  Not good for making
tile tools as they are as soft as, if not softer than, the stone
used to hold them.
There is also the floor tile.  These are intended to be walked on
and thus are a lot harder than the wall tiles.  These are usually
done in smaller sizes and are of a single color and need to have
wax applied to get a polished surface.  They also tend to look
like they were cast in a closed mold rather than the wall tile
that looks like it got painted on a half mold.
I'll note that you can also use glass cut up for tiles as well as
hard stones to do the job.  I'm mostly using glass for tools now
as the glass is readily available.
Bob May

rmay at nethere.com
http: slash /nav.to slash bobmay
http: slash /bobmay dot astronomy.net



From burrjaw at earthlink.net  Tue May 12 12:07:28 2009
From: burrjaw at earthlink.net (Jim Burrows)
Date: Mon, 11 May 2009 20:07:28 -0700
Subject: [ATM] Hindle test ray trace.
Message-ID: <E1M41Jm-0006kk-Iw@elasmtp-dupuy.atl.sa.earthlink.net>

I've programmed up a (careful - no paraxial assumptions) ray trace of 
the Hindle test of a convex secondary.  The zip file contains a 
sample input file, test.txt.  At the start of running the executable, 
hin_set.exe, the user can change any or all of the 8 parameters that 
describe the test:
         Hindle ROC, diameter, hole diameter,
         secondary ROC, diameter, conic constant,
         Hindle-secondary separation,
         secondary-source distance.
At the end of the run, test.txt is replaced by a file of the same 
name with the chosen input parameters and the result of the ray trace.

By the way, the first three numbers in test.txt are the parameters of 
my 10" f/1 Hindle sphere (0.4 nm RMS!), so anyone can see if 
borrowing it would work for a Hindle test of their secondary.

Download:
         http://home.earthlink.net/~burrjaw/public/h_trace.zip 
(2009-05-12, Win32, 305.9 k)

         -- Jim Burrows
         -- http://home.earthlink.net/~burrjaw
         -- mailto:burrjaw at earthlink.net
         -- Seattle N47.4723 W122.3662 (WGS84)


From jonas.zaveckas at gmail.com  Wed May 13 16:11:59 2009
From: jonas.zaveckas at gmail.com (Jonas)
Date: Wed, 13 May 2009 10:11:59 +0300
Subject: [ATM] First time polish
Message-ID: <4A0A72BF.6090802@gmail.com>

Hello,
I'm polishing my first mirror. 10 hours already done. Have read some
polishing guides, but again, some uncertainty in mind on judging for
quality.

I'm inspecting surface with x10 magnifier and some LED light coming from
bottom side under ~45 deg. angle. If the light comes under angle from
above - I can not see anything at all, only largest dust particles.
Looks like there are still some tiny pits near the edge. Think they will
disappear after hour or two. These do not cause any problems to my
judgment. But I always see plenty of some shiny dust specks on the
surface. Most of them go away if I wipe surface with some gentle cloth
for lens cleaning (haven't saw any that can not be wiped out, actually).
Is there any way to clean them away before checking? At least majority
of them. I am cleaning under water stream in the sink and wiping with
fingers. Maybe some chemical glass cleaner would work better? Or maybe,
if the glass is not polished enough then the amount of dust just shows
that dust tends to stick to uneven glass surface? When polished
completely dust will be washed away just by water stream without
sticking? Looks like there is more dust on the edges, anyway. But this
can be false impression.

I've also tried laser checking. But this gives me a total frustration.
Yes, dust particles can be seen clearly. But all surface from the center
to the edge shows some granularity seen by the naked eye. And it seems
to be not from laser but is on the surface - it is not 'attached' to the
laser beam. Does this show that I have some rough surface from too much
pressing glass to the tool (I am using MOT only, 1/3 COC), for example?
Or maybe it is not possible to get surface so clean, that there will
always be some tiny particles on it (polishing powder, for example)? I
feel somehow uncertain about this laser method. I can see what needs to
be polished with magnifier and LED on the edge but see no difference
using laser here...


Jonas

From jroyston at gmx.de  Wed May 13 16:30:49 2009
From: jroyston at gmx.de (Jeremy Royston)
Date: Wed, 13 May 2009 09:30:49 +0200
Subject: [ATM] First time polish
In-Reply-To: <4A0A72BF.6090802@gmail.com>
References: <4A0A72BF.6090802@gmail.com>
Message-ID: <000701c9d39c$bdb3dcd0$391b9670$@de>

Hello Jonas,
	It's usually best to clean the mirror as you say, then with
distilled water. Stand it on its edge on a clean cloth or a few layers of
Kleenex, then let it drain and dry. Don't tounch it with anything
The old method was to look at it in sunlight, near the reflection of the
sun. A laser pointer is much better, see if there are changes in appearance
from centre to edge. 
You didn't mention which polishing medium you used, or the size of the
mirror. Ten hours should be more than sufficient with cerium oxide and an 8"
pyrex mirror

Best wishes, Jerry

-----Urspr?ngliche Nachricht-----
Von: atm-bounces at atmlist.net [mailto:atm-bounces at atmlist.net] Im Auftrag von
Jonas
Gesendet: 13 May 2009 09:12
An: atm at atmlist.net
Betreff: [ATM] First time polish

Hello,
I'm polishing my first mirror. 10 hours already done. Have read some
polishing guides, but again, some uncertainty in mind on judging for
quality.
...snip


From jonas.zaveckas at gmail.com  Wed May 13 18:32:07 2009
From: jonas.zaveckas at gmail.com (Jonas)
Date: Wed, 13 May 2009 12:32:07 +0300
Subject: [ATM] First time polish
In-Reply-To: <000701c9d39c$bdb3dcd0$391b9670$@de>
References: <4A0A72BF.6090802@gmail.com> <000701c9d39c$bdb3dcd0$391b9670$@de>
Message-ID: <4A0A9397.8050803@gmail.com>

Jeremy Royston wrote:
> Hello Jonas,
> 	It's usually best to clean the mirror as you say, then with
> distilled water. Stand it on its edge on a clean cloth or a few layers of
> Kleenex, then let it drain and dry. Don't tounch it with anything
Not good... I was touching it. Will never do it again. Seems no
scratches for the moment, but who knows...

> The old method was to look at it in sunlight, near the reflection of the
> sun. A laser pointer is much better, see if there are changes in appearance
> from centre to edge.
There is some very minute difference on the edge. Something like last 4
mm to the edge. All of the remaining surface seems quite uniform. This
is much easier seen with magnifier. Some tiny pits available. And their
number is now rapidly decreasing with every hour of polishing.


> You didn't mention which polishing medium you used, or the size of the
> mirror. Ten hours should be more than sufficient with cerium oxide and an 8"
> pyrex mirror
> 
6" pyrex, cerium oxide. I suspect that some of those 10 hours were not
sufficiently effective. Following only written recommendations should be
the cause of such a long time - it took some time to find polisher
concentration, how to hold mirror while not touching the edges, how to
fix the tool for comfortable movement and so on. I was using only MOT
and the last inch of the edge started to show significant change only
after few hours. I'm doing one hour of polishing per day. Cold pressing
before each session for ~45 minutes. With 4 kg on top. By the way, I'm
forced to make some breaks of a few minutes long during session. This,
I'm afraid is not very good. Before leaving I'm leaving glass on tool
and covering everything with some plastic box not to lose heat and moisture.

Will spend additional hour or two. My biggest fear is surface roughness.
Will I discover it with focal testing later? If I'll miss some pits its
not a big deal, I think? Most of the bright spots that I see are dust
particles, for sure. If  some real pits will hide between them that will
not make noticeable difference in final quality? Dust on coated mirror
should have greater effect?

Jonas

From dlwebb at canit.se  Wed May 13 19:30:18 2009
From: dlwebb at canit.se (Dominic-Luc Webb)
Date: Wed, 13 May 2009 12:30:18 +0200 (MET DST)
Subject: [ATM] silvering supplies
Message-ID: <Pine.LNX.4.44.0905131223410.23803-100000@uno.canit.se>


Can anyone recommend a place in USA to buy chemicals
for silivering (yeah, I mean specifically silvering)?
I will be in Berkeley, CA and doing some driving around
SF Bay Area. Otherwise can order by mail, but where to
find it?

Application: trying different mirror configs and 50:50
dichroics, amongst others. I am after enough for a
few jobs on a 13" mirror and some much smaller pieces.
As usual for me, I have a few odd experiments as well.

Dominic-Luc Webb


From richard at foucault.co.uk  Wed May 13 20:06:08 2009
From: richard at foucault.co.uk (Richard in the UK)
Date: Wed, 13 May 2009 12:06:08 +0100
Subject: [ATM] silvering supplies
In-Reply-To: <Pine.LNX.4.44.0905131223410.23803-100000@uno.canit.se>
References: <Pine.LNX.4.44.0905131223410.23803-100000@uno.canit.se>
Message-ID: <19810193499.20090513120608@foucault.co.uk>

Hello Dominic-Luc,

Wednesday, May 13, 2009, 11:30:18 AM, you wrote:

> Can anyone recommend a place in USA to buy chemicals
> for silivering

The silvering I did decades ago left explosive by-products. If it
still does, it may be worth some thought about if you will be allowed
to carry it on a plane..

-- 
Best regards,
 Richard in the UK


From lopez at mv.mv.com  Wed May 13 20:24:43 2009
From: lopez at mv.mv.com (Lawrence D. Lopez)
Date: Wed, 13 May 2009 07:24:43 -0400
Subject: [ATM] silvering supplies
In-Reply-To: <19810193499.20090513120608@foucault.co.uk>
References: <Pine.LNX.4.44.0905131223410.23803-100000@uno.canit.se>
	<19810193499.20090513120608@foucault.co.uk>
Message-ID: <4A0AADFB.8020704@mv.mv.com>

Richard:

Some notes on the silvering process.
http://www.hse.gov.uk/foi/internalops/fod/oc/600-699/687_7.pdf

Larry




Richard in the UK wrote:
> Hello Dominic-Luc,
>
> Wednesday, May 13, 2009, 11:30:18 AM, you wrote:
>
>   
>> Can anyone recommend a place in USA to buy chemicals
>> for silivering
>>     
>
> The silvering I did decades ago left explosive by-products. If it
> still does, it may be worth some thought about if you will be allowed
> to carry it on a plane..
>
>   


From shane at ct-astronomer.com  Wed May 13 22:02:01 2009
From: shane at ct-astronomer.com (Shane LaPierre)
Date: Wed, 13 May 2009 09:02:01 -0400
Subject: [ATM] First time polish
In-Reply-To: <4A0A9397.8050803@gmail.com>
References: <4A0A72BF.6090802@gmail.com> <000701c9d39c$bdb3dcd0$391b9670$@de>
	<4A0A9397.8050803@gmail.com>
Message-ID: <9DF697E8-907E-4FBF-977A-D9938B23521D@ct-astronomer.com>

Sounds like you are doing just fine to me.  Pits are vanishing.  Check  
under knife-edge for surface quality.  If it's smooth, and there are  
no major edge and zone issues, you are progressing perfectly.  Biggest  
thing with a small mirror is to keep your strokes short.  You can  
always switch to TOT to work the edges faster... but I would keep MOT  
until you are all polished out unless you have a turned edge.  MOT  
works the edges last, so when your edges are polished all the way out  
then you are done polishing.

Best luck,
Shane


>
> Will spend additional hour or two. My biggest fear is surface  
> roughness.
> Will I discover it with focal testing later? If I'll miss some pits  
> its
> not a big deal, I think? Most of the bright spots that I see are dust
> particles, for sure. If  some real pits will hide between them that  
> will
> not make noticeable difference in final quality? Dust on coated mirror
> should have greater effect?
>
> Jonas
> _______________________________________________
> ATM mailing list http://www.atmlist.net/


From mjc5 at psu.edu  Wed May 13 22:02:34 2009
From: mjc5 at psu.edu (Michael Coslo)
Date: Wed, 13 May 2009 09:02:34 -0400
Subject: [ATM] [Fwd: Re:  Polyurethane tiles]
In-Reply-To: <004201c9d342$f4aab420$8f78fea9@amd>
References: <4A069FDF.1070406@mweb.co.za> <000601c9d1b7$03edb460$8f78fea9@amd>
	<D6B17F02-CC77-492A-BFE8-6441DDFA25F2@psu.edu>
	<004201c9d342$f4aab420$8f78fea9@amd>
Message-ID: <7CFE3BD6-DCFE-469C-B5B0-9C4B50912744@psu.edu>


On May 12, 2009, at 4:48 PM, Bob May wrote:

> When you watch what you're doing as to water on the tool as well
> as doing a proper grinding procedure (no long strokes) the
> probability of having a lock becomes extremely slim.

True. But when I was a rank noob, I didn't know that yet. So when I  
channel the tool now, it's just coming from a lesson I'd learned. I do  
use a proper amount of water now, but when you get a lock, you'll do a  
lot of stuff to avoid getting another one. It also fits in well with  
my process.


-73 de Mike N3LI -



From blaktony86 at yahoo.com  Wed May 13 22:29:16 2009
From: blaktony86 at yahoo.com (TONY B)
Date: Wed, 13 May 2009 08:29:16 CDT
Subject: [ATM] silvering supplies
Message-ID: <mailman.900.1242221361.7676.atm@atmlist.net>

Any local chem supply store will have all the chemicals you need for silvering.
-----Original Message-----
Date: Wednesday, May 13, 2009 5:31:35 am
To: "ATM Superheros" <atm at atmlist.net>
From: "Dominic-Luc Webb" <dlwebb at canit.se>
Subject: [ATM] silvering supplies


Can anyone recommend a place in USA to buy chemicals
for silivering (yeah, I mean specifically silvering)?
I will be in Berkeley, CA and doing some driving around
SF Bay Area. Otherwise can order by mail, but where to
find it?

Application: trying different mirror configs and 50:50
dichroics, amongst others. I am after enough for a
few jobs on a 13" mirror and some much smaller pieces.
As usual for me, I have a few odd experiments as well.

Dominic-Luc Webb

_______________________________________________
ATM mailing list http://www.atmlist.net/



From dlwebb at canit.se  Wed May 13 22:30:04 2009
From: dlwebb at canit.se (Dominic-Luc Webb)
Date: Wed, 13 May 2009 15:30:04 +0200 (MET DST)
Subject: [ATM] silvering supplies
In-Reply-To: <19810193499.20090513120608@foucault.co.uk>
Message-ID: <Pine.LNX.4.44.0905131522190.32328-100000@uno.canit.se>


On Wed, 13 May 2009, Richard in the UK wrote:

> Hello Dominic-Luc,
>
> Wednesday, May 13, 2009, 11:30:18 AM, you wrote:
>
> > Can anyone recommend a place in USA to buy chemicals
> > for silivering
>
> The silvering I did decades ago left explosive by-products. If it
> still does, it may be worth some thought about if you will be allowed
> to carry it on a plane..
>
> --
> Best regards,
>  Richard in the UK

Hi and nice to hear from you, Richard in the UK.

This did come to mind, but thinking small amounts un-opened
might well be OK. Small kits for 8-12" mirrors were available
in a few shops with no special warnings when I was a kid in
California. A number of the kids in my neighborhood did
silvering without problems. Watching a piece of glass suddenly
turn into a mirror in front of one's eye is a fun experience
for an 8 year old. The method never entirely lost its luster,
still having useful applications.

Dominic


From blaktony86 at yahoo.com  Wed May 13 22:33:49 2009
From: blaktony86 at yahoo.com (TONY B)
Date: Wed, 13 May 2009 08:33:49 CDT
Subject: [ATM] First time polish
Message-ID: <mailman.901.1242221634.7676.atm@atmlist.net>

 I would start doing some TOT work to help prevent TDE. Sounds to me like your nearly polished out. What kind of bevel do you have? You will spend many more hours figuring so if your nearly polished out, i would start testing. The ronchi test will clearly show you if you have any TDE.
-----Original Message-----
Date: Wednesday, May 13, 2009 2:13:15 am
To: atm at atmlist.net
From: "Jonas" <jonas.zaveckas at gmail.com>
Subject: [ATM] First time polish

Hello,
I'm polishing my first mirror. 10 hours already done. Have read some
polishing guides, but again, some uncertainty in mind on judging for
quality.

I'm inspecting surface with x10 magnifier and some LED light coming from
bottom side under ~45 deg. angle. If the light comes under angle from
above - I can not see anything at all, only largest dust particles.
Looks like there are still some tiny pits near the edge. Think they will
disappear after hour or two. These do not cause any problems to my
judgment. But I always see plenty of some shiny dust specks on the
surface. Most of them go away if I wipe surface with some gentle cloth
for lens cleaning (haven't saw any that can not be wiped out, actually).
Is there any way to clean them away before checking? At least majority
of them. I am cleaning under water stream in the sink and wiping with
fingers. Maybe some chemical glass cleaner would work better? Or maybe,
if the glass is not polished enough then the amount of dust just shows
that d


From blaktony86 at yahoo.com  Wed May 13 23:38:27 2009
From: blaktony86 at yahoo.com (TONY BLAKESLEY)
Date: Wed, 13 May 2009 07:38:27 -0700 (PDT)
Subject: [ATM] First time polish
In-Reply-To: <4A0AD555.3080604@gmail.com>
Message-ID: <528056.30423.qm@web81906.mail.mud.yahoo.com>

There are many sources that says that if you work too much MOT you can get TDE. I would Ronchi test ASAP and check your figure. If you must polish out the edge some more I would do some TOT work. TOT work will not destroy a sphere.
?
I am combating TDE because of too much MOT work. TOT defintley is helping. I have found that if you work TOT, offset your tool about an inch or two, and do long tangential strokes that this helps bring down the TDE substantially. This works well without destroying your figure. Small laps to help correct TDE may be effective, but causes many zones that can be difficult to smooth out. 
?
I also had some minor pits on the edge but now that I have worked about 3hrs+ combating TDE, my pits have dissappeared! I think you are ready to build that tester now... 

--- On Wed, 5/13/09, Jonas <jonas.zaveckas at gmail.com> wrote:

From: Jonas <jonas.zaveckas at gmail.com>
Subject: Re: [ATM] First time polish
To: "TONY B" <blaktony86 at yahoo.com>
Date: Wednesday, May 13, 2009, 9:12 AM

I've read that 1/3 COC does not generate TDE? But the mirror is small
(6") my hands are big...Some edge warming could have occured. If I do
some MOT for the remaining few hours maybe there is a danger of damaging
a sphere (if there was any before, of course)?

Maybe the next step before finishing polishing will be making a tester.

The remaining bevel is about 1.5-2 mm

Jonas
TONY B wrote:
>  I would start doing some TOT work to help prevent TDE. Sounds to me like
your nearly polished out. What kind of bevel do you have? You will spend many
more hours figuring so if your nearly polished out, i would start testing. The
ronchi test will clearly show you if you have any TDE.

From mbartels at bbastrodesigns.com  Wed May 13 23:44:16 2009
From: mbartels at bbastrodesigns.com (mbartels at bbastrodesigns.com)
Date: Wed, 13 May 2009 08:44:16 -0600
Subject: [ATM] First time polish
In-Reply-To: <528056.30423.qm@web81906.mail.mud.yahoo.com>
References: <528056.30423.qm@web81906.mail.mud.yahoo.com>
Message-ID: <20090513084416.qvrduas1lw08c4cs@mail.bbastrodesigns.com>

> There are many sources that says that if you work too much MOT you   
> can get TDE. I would Ronchi test ASAP and check your figure. If you   
> must polish out the edge some more I would do some TOT work. TOT   
> work will not destroy a sphere.


Just to show that there are deeper factors at work here <smile>...  I  
*never* get TDE and I *only* do MOT (for polishing *and* figuring).

Mel Bartels



From atm_ken_hunter at yahoo.com  Wed May 13 23:57:41 2009
From: atm_ken_hunter at yahoo.com (Ken Hunter)
Date: Wed, 13 May 2009 07:57:41 -0700 (PDT)
Subject: [ATM] silvering supplies
Message-ID: <322945.32551.qm@web52703.mail.re2.yahoo.com>


Doesn't much matter what you try to carry on board... they won't even let you take your tooth paste and shampoo on most flights now.

Ken Hunter


--- On Wed, 5/13/09, Dominic-Luc Webb <dlwebb at canit.se> wrote:

> From: Dominic-Luc Webb <dlwebb at canit.se>
> Subject: Re: [ATM] silvering supplies
> To: "ATM Superheros" <atm at atmlist.net>
> Date: Wednesday, May 13, 2009, 8:30 AM
> 
> On Wed, 13 May 2009, Richard in the UK wrote:
> 
> > Hello Dominic-Luc,
> >
> > Wednesday, May 13, 2009, 11:30:18 AM, you wrote:
> >
> > > Can anyone recommend a place in USA to buy
> chemicals
> > > for silivering
> >
> > The silvering I did decades ago left explosive
> by-products. If it
> > still does, it may be worth some thought about if you
> will be allowed
> > to carry it on a plane..
> >
> > --
> > Best regards,
> >? Richard in the UK
> 
> Hi and nice to hear from you, Richard in the UK.
> 
> This did come to mind, but thinking small amounts
> un-opened
> might well be OK. Small kits for 8-12" mirrors were
> available
> in a few shops with no special warnings when I was a kid
> in
> California. A number of the kids in my neighborhood did
> silvering without problems. Watching a piece of glass
> suddenly
> turn into a mirror in front of one's eye is a fun
> experience
> for an 8 year old. The method never entirely lost its
> luster,
> still having useful applications.
> 
> Dominic
> 
> _______________________________________________
> ATM mailing list http://www.atmlist.net/
> 


      

From richard at foucault.co.uk  Wed May 13 23:58:58 2009
From: richard at foucault.co.uk (Richard in the UK)
Date: Wed, 13 May 2009 15:58:58 +0100
Subject: [ATM] silvering supplies
In-Reply-To: <Pine.LNX.4.44.0905131522190.32328-100000@uno.canit.se>
References: <19810193499.20090513120608@foucault.co.uk>
	<Pine.LNX.4.44.0905131522190.32328-100000@uno.canit.se>
Message-ID: <1868224931.20090513155858@foucault.co.uk>

Hello Dominic-Luc,

Wednesday, May 13, 2009, 2:30:04 PM, you wrote:

> This did come to mind, but thinking small amounts un-opened
> might well be OK.

You may well be OK, it's a matter of if you are happy with "might".
You still can't carry drinking water on flights in some parts of the
world.

> The method never entirely lost its luster,
> still having useful applications.

You're not kidding - almost every wall mirror you ever look in has
been Silvered.

-- 
Best regards,
 Richard in the UK


From blaktony86 at yahoo.com  Thu May 14 00:21:54 2009
From: blaktony86 at yahoo.com (TONY BLAKESLEY)
Date: Wed, 13 May 2009 08:21:54 -0700 (PDT)
Subject: [ATM] First time polish
In-Reply-To: <20090513084416.qvrduas1lw08c4cs@mail.bbastrodesigns.com>
Message-ID: <162199.9295.qm@web81903.mail.mud.yahoo.com>

Mel,
?
I think your title should now become a PTM (professional telescope maker)! What size laps do you use when you work MOT? Do you use oversize laps? 
?
I have only done 3 mirrors, but every mirror I have done thus far has had some TDE. I must be doing something wrong....
?
-Tony

--- On Wed, 5/13/09, mbartels at bbastrodesigns.com <mbartels at bbastrodesigns.com> wrote:

From: mbartels at bbastrodesigns.com <mbartels at bbastrodesigns.com>
Subject: Re: [ATM] First time polish
To: atm at atmlist.net
Date: Wednesday, May 13, 2009, 9:44 AM

> There are many sources that says that if you work too much MOT you  can get
TDE. I would Ronchi test ASAP and check your figure. If you  must polish out the
edge some more I would do some TOT work. TOT  work will not destroy a sphere.


Just to show that there are deeper factors at work here <smile>...  I
*never* get TDE and I *only* do MOT (for polishing *and* figuring).

Mel Bartels


_______________________________________________
ATM mailing list http://www.atmlist.net/

From jhm.vangastel at ziggo.nl  Thu May 14 00:58:12 2009
From: jhm.vangastel at ziggo.nl (Jan van Gastel)
Date: Wed, 13 May 2009 17:58:12 +0200
Subject: [ATM] First time polish
References: <528056.30423.qm@web81906.mail.mud.yahoo.com>
	<20090513084416.qvrduas1lw08c4cs@mail.bbastrodesigns.com>
Message-ID: <7A7D758A19164A4E8E61DAD7DB82D7CD@niks03981037eb>

I am figuring my 8" f/3.85 also only MOT and only using 'classic' W-strokes: 
normal parabolization strokes and variations (more center, more edge). Three 
or four times I arrived at 1/4 -1/5lamda (PV=wavefront), twice at around 1/6 
lambda and once at 1/7.35 lambda. The difference between the last and for 
instance 1/12 is not large, but I have not succeeded yet. I want it 1/8 or 
better. I am going back to a sphere now, but I have to make a new lap first.

Jan
http://members.ziggo.nl/jhm.vangastel/Astronomy/


----- Original Message ----- 
From: <mbartels at bbastrodesigns.com>
To: <atm at atmlist.net>
Sent: Wednesday, May 13, 2009 16:44
Subject: Re: [ATM] First time polish


>> There are many sources that says that if you work too much MOT you   can 
>> get TDE. I would Ronchi test ASAP and check your figure. If you   must 
>> polish out the edge some more I would do some TOT work. TOT   work will 
>> not destroy a sphere.
>
>
> Just to show that there are deeper factors at work here <smile>...  I 
> *never* get TDE and I *only* do MOT (for polishing *and* figuring).
>
> Mel Bartels
>
>
> _______________________________________________
> ATM mailing list http://www.atmlist.net/ 


From Mitch_Bisnauth at Cknainc.com  Thu May 14 01:09:30 2009
From: Mitch_Bisnauth at Cknainc.com (Mitch_Bisnauth at Cknainc.com)
Date: Wed, 13 May 2009 11:09:30 -0500
Subject: [ATM] best W-stroke
In-Reply-To: <7A7D758A19164A4E8E61DAD7DB82D7CD@niks03981037eb>
Message-ID: <OF602BB0EC.4888B110-ON862575B5.005868B5-862575B5.0058DB4E@Cknainc.com>

....as a discussion point...can we share our "best" W-stroke? --- the one 
that's easy to do by hand and generates a repeatable sphere w/o TDE...

From hermit at outofoptions.org  Thu May 14 01:19:38 2009
From: hermit at outofoptions.org (hermit)
Date: Wed, 13 May 2009 12:19:38 -0400
Subject: [ATM] best W-stroke
In-Reply-To: <OF602BB0EC.4888B110-ON862575B5.005868B5-862575B5.0058DB4E@Cknainc.com>
References: <OF602BB0EC.4888B110-ON862575B5.005868B5-862575B5.0058DB4E@Cknainc.com>
Message-ID: <4A0AF31A.9050005@outofoptions.org>

Mitch_Bisnauth at Cknainc.com wrote:
> ....as a discussion point...can we share our "best" W-stroke? --- the one 
> that's easy to do by hand and generates a repeatable sphere w/o TDE...
> _______________________________________________
> ATM mailing list http://www.atmlist.net/
>   
Big fat "depends" on this one.  I stay with little side to side early 
on.  I think the wider strokes are useful at the end to start getting 
rid of 'stuff' along with frequent presses.

Ken Lowther

From dlwebb at canit.se  Thu May 14 01:44:57 2009
From: dlwebb at canit.se (Dominic-Luc Webb)
Date: Wed, 13 May 2009 18:44:57 +0200 (MET DST)
Subject: [ATM] silvering supplies
In-Reply-To: <1868224931.20090513155858@foucault.co.uk>
Message-ID: <Pine.LNX.4.44.0905131824010.31551-100000@uno.canit.se>


On Wed, 13 May 2009, Richard in the UK wrote:

> > This did come to mind, but thinking small amounts un-opened
> > might well be OK.
>
> You may well be OK, it's a matter of if you are happy with "might".
> You still can't carry drinking water on flights in some parts of the
> world.

Baggage issues can quickly be sorted out with a call to the
security people a couple days before the flight. So far, I
have had no problems actually bringing things back to
Sweden. Maybe some scrutiny before the flight, but never
stopped from bringing anything. However, common sense tells
us to put unusual items into check-in baggage, which is more
permissive. Primary ingredient for silvering is silver nitrate,
which is hard to find around here. Other ingredients do not
need to be transported.

As an amusing side note, fire extinguishers of any kind
are banned on both carry-on and check-in baggage.

Dominic


From vladimir.galogaza1 at zg.t-com.hr  Thu May 14 05:00:31 2009
From: vladimir.galogaza1 at zg.t-com.hr (Vladimir Galogaza)
Date: Wed, 13 May 2009 22:00:31 +0200
Subject: [ATM] First time polish
References: <4A0A72BF.6090802@gmail.com> <000701c9d39c$bdb3dcd0$391b9670$@de>
Message-ID: <E67470FD4AED4B02BB683A7BE8FEFF61@piv555a133b59e>

 >Don't touch it with anything 

?????????????????????????

What harm can be done to the mirror during washing
at the polishing stage. It is very unlikely that cleaning will
attack  the surface more than CeO.
Caution is understandable but scaring somebody from
doing something without well explained reasoning behind it
is not in the good ATM spirit. Result is not spreading the 
knowledge but generating urban legends.

Regards
Vladimir.




From foreilly at bestweb.net  Thu May 14 05:21:26 2009
From: foreilly at bestweb.net (Francis J. O'Reilly)
Date: Wed, 13 May 2009 16:21:26 -0400
Subject: [ATM] First time polish
References: <4A0A72BF.6090802@gmail.com> <000701c9d39c$bdb3dcd0$391b9670$@de>
	<E67470FD4AED4B02BB683A7BE8FEFF61@piv555a133b59e>
Message-ID: <237CE65F852F425E92B1FB2577C08947@D5GHLR11>

Actually, the only harm that I see from touching the mirror while polishing 
is getting sebum on the surface which can give a false impression that light 
does not pass through the surface of the mirror, thus giving the impression 
of an imperfectly polished surface.

Imagine if you could scratch the surface of the glass with your fingers, why 
use grit?

Francis J. O'Reilly
----- Original Message ----- 
From: "Vladimir Galogaza" <vladimir.galogaza1 at zg.t-com.hr>
To: "ATM List" <atm at atmlist.net>
Sent: Wednesday, May 13, 2009 4:00 PM
Subject: Re: [ATM] First time polish


> >Don't touch it with anything
>
> ?????????????????????????
>
> What harm can be done to the mirror during washing
> at the polishing stage. It is very unlikely that cleaning will
> attack  the surface more than CeO.
> Caution is understandable but scaring somebody from
> doing something without well explained reasoning behind it
> is not in the good ATM spirit. Result is not spreading the knowledge but 
> generating urban legends.
>
> Regards
> Vladimir.
>
>
>
> _______________________________________________
> ATM mailing list http://www.atmlist.net/ 


From wa4guu at verizon.net  Thu May 14 05:48:04 2009
From: wa4guu at verizon.net (Jerry)
Date: Wed, 13 May 2009 16:48:04 -0400
Subject: [ATM] First time polish
In-Reply-To: <237CE65F852F425E92B1FB2577C08947@D5GHLR11>
Message-ID: <7F8236F2D9CC44EE807C9CC3562893E8@D85SJB21>

I don't think he meant it would be catastrophic to touch it with something.
I think he just meant that to allow it to dry without touching it, such as
wiping with a paper towel and possibly putting dust, oil or other
contaminant on the surface. 



-----Original Message-----
From: atm-bounces at atmlist.net [mailto:atm-bounces at atmlist.net] On Behalf Of
Francis J. O'Reilly
Sent: Wednesday, May 13, 2009 4:21 PM
To: Vladimir Galogaza; ATM List
Subject: Re: [ATM] First time polish

Actually, the only harm that I see from touching the mirror while polishing 
is getting sebum on the surface which can give a false impression that light

does not pass through the surface of the mirror, thus giving the impression 
of an imperfectly polished surface.

Imagine if you could scratch the surface of the glass with your fingers, why

use grit?

Francis J. O'Reilly
----- Original Message ----- 
From: "Vladimir Galogaza" <vladimir.galogaza1 at zg.t-com.hr>
To: "ATM List" <atm at atmlist.net>
Sent: Wednesday, May 13, 2009 4:00 PM
Subject: Re: [ATM] First time polish


> >Don't touch it with anything
>
> ?????????????????????????
>
> What harm can be done to the mirror during washing
> at the polishing stage. It is very unlikely that cleaning will
> attack  the surface more than CeO.
> Caution is understandable but scaring somebody from
> doing something without well explained reasoning behind it
> is not in the good ATM spirit. Result is not spreading the knowledge but 
> generating urban legends.
>
> Regards
> Vladimir.
>
>
>
> _______________________________________________
> ATM mailing list http://www.atmlist.net/ 

_______________________________________________
ATM mailing list http://www.atmlist.net/


From rmay at nethere.com  Thu May 14 07:56:13 2009
From: rmay at nethere.com (Bob May)
Date: Wed, 13 May 2009 15:56:13 -0700
Subject: [ATM] First time polish
References: <4A0A72BF.6090802@gmail.com> <000701c9d39c$bdb3dcd0$391b9670$@de>
	<4A0A9397.8050803@gmail.com>
Message-ID: <002c01c9d41e$04d14220$8f78fea9@amd>

If you haven't put it to the Foucault test, it is now time to do
so.  You will see the bright edge area where the glass isn't
finished being polished and you will be able to see the shape
that the glass is in.
I vary in answers when I see TDE from late polishing of the edge,
sometimes telling the guy to do TOT or just do short strokes.
If you're lucky, a TOT bit of work will get you close to a
parabola.  You never know!
As to the dirt on the glass, it seems that no matter how good a
job you do, there is still some dirt that stays on the mirror,
probably falling onto the mirror as you wander about trying to do
a test on it.  I use that dirt to just find the surface in my
eyeloupe.  A good wipe with a dust free cloth usuallly cleans
things off for a while.
Bob May

rmay at nethere.com
http: slash /nav.to slash bobmay
http: slash /bobmay dot astronomy.net



From rmay at nethere.com  Thu May 14 08:08:19 2009
From: rmay at nethere.com (Bob May)
Date: Wed, 13 May 2009 16:08:19 -0700
Subject: [ATM] silvering supplies
References: <Pine.LNX.4.44.0905131522190.32328-100000@uno.canit.se>
Message-ID: <003701c9d41f$b5169300$8f78fea9@amd>

There is always the Peacock Labs chemicals.
http://www.peacocklabs.com/products.htm  for the products site.
Bob May

rmay at nethere.com
http: slash /nav.to slash bobmay
http: slash /bobmay dot astronomy.net



From rmay at nethere.com  Thu May 14 08:16:16 2009
From: rmay at nethere.com (Bob May)
Date: Wed, 13 May 2009 16:16:16 -0700
Subject: [ATM] best W-stroke
References: <OF602BB0EC.4888B110-ON862575B5.005868B5-862575B5.0058DB4E@Cknainc.com>
Message-ID: <004e01c9d420$d1e8b2a0$8f78fea9@amd>

The best that I've seen has been a stroke where the glass never
goes more than 1/3 over the side of the tool.  This means a long
stroke in the middle and shorter ones to the side.  Peter also
has a stroke that just goes around at about the 1/4 offset from
the center that seems to not produce TDE also.  He likes to do
the stroke both with grinding and polishing.  Since the hand
tends not to be able to do a perfect circle, rotating the tool
keeps the work from getting zones in it.
Bob May

rmay at nethere.com
http: slash /nav.to slash bobmay
http: slash /bobmay dot astronomy.net



From mbartels at bbastrodesigns.com  Thu May 14 14:36:28 2009
From: mbartels at bbastrodesigns.com (Mel Bartels)
Date: Wed, 13 May 2009 22:36:28 -0700
Subject: [ATM] First time polish
In-Reply-To: <162199.9295.qm@web81903.mail.mud.yahoo.com>
References: <20090513084416.qvrduas1lw08c4cs@mail.bbastrodesigns.com>
	<162199.9295.qm@web81903.mail.mud.yahoo.com>
Message-ID: <00d901c9d455$f625c970$e2715c50$@com>

>>> 

I think your title should now become a PTM (professional telescope maker)!
What size laps do you use when you work MOT? Do you use oversize laps? 

 

I have only done 3 mirrors, but every mirror I have done thus far has had
some TDE. I must be doing something wrong....

<<< 

 

 

I doubt I would make any more money than I do now, which is zero <smile>.
Better to leave it to the pros like Mike Lockwood.

 

All three of your mirrors have had TDE?  Then what did you do that was in
common across all three mirrors?  Make a list and we'll see what might be
responsible.

 

Mel Bartels


From jroyston at gmx.de  Thu May 14 16:12:26 2009
From: jroyston at gmx.de (Jeremy Royston)
Date: Thu, 14 May 2009 09:12:26 +0200
Subject: [ATM]  First time polish
In-Reply-To: <E67470FD4AED4B02BB683A7BE8FEFF61@piv555a133b59e>
References: <4A0A72BF.6090802@gmail.com> <000701c9d39c$bdb3dcd0$391b9670$@de>
	<E67470FD4AED4B02BB683A7BE8FEFF61@piv555a133b59e>
Message-ID: <000601c9d463$567b1ed0$03715c70$@de>

Hello all,
	I should have qualified the statement "Don't touch it with
anything"!
What I really meant, don't try wiping off the excess water, otherwise you
might get dust on the surface, which one could confuse with pits.
I didn't want to spread any urban legends, just good practice

Best wishes, Jerry

-----Urspr?ngliche Nachricht-----
Von: atm-bounces at atmlist.net [mailto:atm-bounces at atmlist.net] Im Auftrag von
Vladimir Galogaza
Gesendet: 13 May 2009 22:01
An: ATM List
Betreff: Re: [ATM] First time polish

 >Don't touch it with anything 

?????????????????????????

What harm can be done to the mirror during washing
at the polishing stage. It is very unlikely that cleaning will
attack  the surface more than CeO.
Caution is understandable but scaring somebody from
doing something without well explained reasoning behind it
is not in the good ATM spirit. Result is not spreading the 
knowledge but generating urban legends.

Regards
Vladimir.



_______________________________________________
ATM mailing list http://www.atmlist.net/


From dlwebb at canit.se  Thu May 14 18:04:27 2009
From: dlwebb at canit.se (Dominic-Luc Webb)
Date: Thu, 14 May 2009 11:04:27 +0200 (MET DST)
Subject: [ATM] silvering supplies
In-Reply-To: <003701c9d41f$b5169300$8f78fea9@amd>
Message-ID: <Pine.LNX.4.44.0905141103340.23391-100000@uno.canit.se>

On Wed, 13 May 2009, Bob May wrote:

> There is always the Peacock Labs chemicals.
> http://www.peacocklabs.com/products.htm  for the products site.
> Bob May

Thanks! Last post with link only shows products, but couldn't get
to ordering/contact info. This one works.

Dominic


From dlwebb at canit.se  Thu May 14 23:47:40 2009
From: dlwebb at canit.se (Dominic-Luc Webb)
Date: Thu, 14 May 2009 16:47:40 +0200 (MET DST)
Subject: [ATM] silvering reagents and airline baggage
Message-ID: <Pine.LNX.4.44.0905141644250.27774-100000@uno.canit.se>


The Peacock tip paid off quickly. Thanks!

They mentioned two important things...

1. They can ship to Sweden
2. Not even the key ingredient, silver nitrate, is
   allowed on passenger flights.


Close enough. I made arragements to meet with some
people in Berkeley area to give this a try and can
order from Peacock in Sweden. Thanks for this assistance!



Dominic


From Gregg.Swanson at microsoft.com  Fri May 15 00:12:31 2009
From: Gregg.Swanson at microsoft.com (Gregg Swanson)
Date: Thu, 14 May 2009 08:12:31 -0700
Subject: [ATM] silvering reagents and airline baggage
In-Reply-To: <Pine.LNX.4.44.0905141644250.27774-100000@uno.canit.se>
References: <Pine.LNX.4.44.0905141644250.27774-100000@uno.canit.se>
Message-ID: <D46DD847F1D118479ABF4CBB34B875B212548CEB7C@NA-EXMSG-C113.redmond.corp.microsoft.com>

Ok, I have to ask... Why are we trying to silver a mirror?

Gregg

-----Original Message-----
From: atm-bounces at atmlist.net [mailto:atm-bounces at atmlist.net] On Behalf Of Dominic-Luc Webb
Sent: Thursday, May 14, 2009 9:48 AM
To: ATM Superheros
Subject: [ATM] silvering reagents and airline baggage


The Peacock tip paid off quickly. Thanks!

They mentioned two important things...

1. They can ship to Sweden
2. Not even the key ingredient, silver nitrate, is
   allowed on passenger flights.


Close enough. I made arragements to meet with some
people in Berkeley area to give this a try and can
order from Peacock in Sweden. Thanks for this assistance!



Dominic

_______________________________________________
ATM mailing list http://www.atmlist.net/


From dlwebb at canit.se  Fri May 15 00:36:56 2009
From: dlwebb at canit.se (Dominic-Luc Webb)
Date: Thu, 14 May 2009 17:36:56 +0200 (MET DST)
Subject: [ATM] silvering reagents and airline baggage
In-Reply-To: <D46DD847F1D118479ABF4CBB34B875B212548CEB7C@NA-EXMSG-C113.redmond.corp.microsoft.com>
Message-ID: <Pine.LNX.4.44.0905141729220.3606-100000@uno.canit.se>

On Thu, 14 May 2009, Gregg Swanson wrote:

> Ok, I have to ask... Why are we trying to silver a mirror?
>
> Gregg

I normally aluminize. I will test a a number of permutations
in which I will have a surface that will then quickly be
changed. Commercial aluminizing is not practical. Also, I
am making some comparatively small pieces that will be 50:50
beam splitters that will end up in sealed environment. It is
comparatively cheap and seems pretty straighforward to make
a semi-reflective surface by silvering. Others have succeeded
anyway. I plan to also be successful.

Dominic


From alcom_ny at yahoo.com  Fri May 15 03:22:04 2009
From: alcom_ny at yahoo.com (alik alik)
Date: Thu, 14 May 2009 11:22:04 -0700 (PDT)
Subject: [ATM] my first mirror
Message-ID: <942095.62348.qm@web50001.mail.re2.yahoo.com>

Hi

caould somebody please tell me what chemicals i need to make a mirror?
i have ordered dental stones to make the tool, but what kind of chemical do i need?? and where can i buy them?

Thank you
Alex


      

From vladimir.galogaza1 at zg.t-com.hr  Fri May 15 03:33:48 2009
From: vladimir.galogaza1 at zg.t-com.hr (Vladimir Galogaza)
Date: Thu, 14 May 2009 20:33:48 +0200
Subject: [ATM] silvering reagents and airline baggage
References: <Pine.LNX.4.44.0905141729220.3606-100000@uno.canit.se>
Message-ID: <DE816762881D4354AFA469D6BD025E53@piv555a133b59e>

>Iam making some comparatively small pieces that will be 50:50
>beam splitters that will end up in sealed environment. 

How will you controll the process to achieve 50:50 (or any
other predetrimned ratio)?

Regards
Vladimir.

From jkoptic at juno.com  Fri May 15 03:45:28 2009
From: jkoptic at juno.com (Jarvis Krumbein)
Date: Thu, 14 May 2009 11:45:28 -0700
Subject: [ATM] silvering reagents and airline baggage
Message-ID: <20090514.114528.3932.0.jkoptic@juno.com>

Vladimir, a simple method can be found in John Strong's "Procedures in
Experimental Physics, published by Prentis-Hall".  Take a look at page
157 and 158 for the "Rochelle Salt Process" of silvering.  Strong's book
has been out of print for quite a long time now but it is still one of
the best volumes available. 

Jarvis Krumbein

On Thu, 14 May 2009 20:33:48 +0200 "Vladimir Galogaza"
<vladimir.galogaza1 at zg.t-com.hr> writes:
> >Iam making some comparatively small pieces that will be 50:50
> >beam splitters that will end up in sealed environment. 
> 
> How will you controll the process to achieve 50:50 (or any
> other predetrimned ratio)?
> 
> Regards
> Vladimir.
> _______________________________________________
> ATM mailing list http://www.atmlist.net/
> 

____________________________________________________________
Click here to find the perfect picture with our powerful photo search features.
http://thirdpartyoffers.juno.com/TGL2141/fc/BLSrjpTEuJDhlOHaHqlJYvrygM6DFnNYhwGyP1JoPMGIoyG7rTYIDOUJU8w/

From rmay at nethere.com  Fri May 15 05:13:23 2009
From: rmay at nethere.com (Bob May)
Date: Thu, 14 May 2009 13:13:23 -0700
Subject: [ATM] my first mirror
References: <942095.62348.qm@web50001.mail.re2.yahoo.com>
Message-ID: <001f01c9d4d0$704ab4c0$8f78fea9@amd>

I assume from your phrasing of the question that you're not in
the English speaking world where things are quite easy to get.
There is www.gotgrit.com as one source of all you need.
Basically you need some Silicon Carbide and Aluminum Oxide grit
of various sizes to do the grinding of the glass,   For
polishing, some pitch (tree sap) and Cerium Oxide to do the
polishing.  Check on my website for how it is all done.
For the tool, some thick glass (6mm or thicker) or floor tiles
for a tile tool will be needed.  12mm tiles or the glass cut into
that size is what you want.  Large mirrors can use 25mm tiles if
that is easier to get.
Bob May

rmay at nethere.com
http: slash /nav.to slash bobmay
http: slash /bobmay dot astronomy.net



From rmay at nethere.com  Fri May 15 05:18:55 2009
From: rmay at nethere.com (Bob May)
Date: Thu, 14 May 2009 13:18:55 -0700
Subject: [ATM] silvering reagents and airline baggage
References: <20090514.114528.3932.0.jkoptic@juno.com>
Message-ID: <002401c9d4d1$35678580$8f78fea9@amd>

Bookfinder.com shows the book starting at $40.  Prices up to the
$250 price range are also available if you want to spend that
much money.
Bob May

rmay at nethere.com
http: slash /nav.to slash bobmay
http: slash /bobmay dot astronomy.net



From mjc5 at psu.edu  Fri May 15 04:36:54 2009
From: mjc5 at psu.edu (Michael Coslo)
Date: Thu, 14 May 2009 15:36:54 -0400
Subject: [ATM] silvering reagents and airline baggage
In-Reply-To: <D46DD847F1D118479ABF4CBB34B875B212548CEB7C@NA-EXMSG-C113.redmond.corp.microsoft.com>
References: <Pine.LNX.4.44.0905141644250.27774-100000@uno.canit.se>
	<D46DD847F1D118479ABF4CBB34B875B212548CEB7C@NA-EXMSG-C113.redmond.corp.microsoft.com>
Message-ID: <C8F6EA95-C6E7-4283-BB5C-F051476091FE@psu.edu>


On May 14, 2009, at 11:12 AM, Gregg Swanson wrote:

> Ok, I have to ask... Why are we trying to silver a mirror?


I don't know about Dominic-Luc's reason, but I had several reasons why  
I silvered my mirror:

1. I wanted to do an extended star test. I thought my mirror was  
pretty good via the glass only star test, but conditions can affect  
the test.

2. I was curious to see how a silver surface would last. It turned out  
that with care, it would last over a year. I eventually put a Beral  
coat on it. That year's worth of star testing as well as observing  
convinced me that I was finished figuring. Actually after a month, but  
like I say, I wanted to see how long it would last.

3. Silvering a mirror is very, very cool. It is another tool in the  
toolkit. I recommend it to anyone who makes a telescope. And I did it  
myself.

4. Did I mention it was cool? Fun too.


-73 de Mike N3LI -



From alaskawolfjoe at hotmail.com  Fri May 15 08:43:15 2009
From: alaskawolfjoe at hotmail.com (lance clarke)
Date: Thu, 14 May 2009 19:43:15 -0400
Subject: [ATM] silvering reagents and airline baggage
In-Reply-To: <C8F6EA95-C6E7-4283-BB5C-F051476091FE@psu.edu>
References: <Pine.LNX.4.44.0905141644250.27774-100000@uno.canit.se>
	<D46DD847F1D118479ABF4CBB34B875B212548CEB7C@NA-EXMSG-C113.redmond.corp.microsoft.com>
	<C8F6EA95-C6E7-4283-BB5C-F051476091FE@psu.edu>
Message-ID: <COL113-W794823E59E1B631F4386BFA85E0@phx.gbl>


4. You could be making a schupmann, and silver the back surface of the corrector(and then paint over it to protect it).

 

Lance
 
> Date: Thu, 14 May 2009 15:36:54 -0400
> From: mjc5 at psu.edu
> To: atm at atmlist.net
> Subject: Re: [ATM] silvering reagents and airline baggage
> 
> 
> On May 14, 2009, at 11:12 AM, Gregg Swanson wrote:
> 
> > Ok, I have to ask... Why are we trying to silver a mirror?
> 
> 
> I don't know about Dominic-Luc's reason, but I had several reasons why 
> I silvered my mirror:
> 
> 1. I wanted to do an extended star test. I thought my mirror was 
> pretty good via the glass only star test, but conditions can affect 
> the test.
> 
> 2. I was curious to see how a silver surface would last. It turned out 
> that with care, it would last over a year. I eventually put a Beral 
> coat on it. That year's worth of star testing as well as observing 
> convinced me that I was finished figuring. Actually after a month, but 
> like I say, I wanted to see how long it would last.
> 
> 3. Silvering a mirror is very, very cool. It is another tool in the 
> toolkit. I recommend it to anyone who makes a telescope. And I did it 
> myself.
> 
> 4. Did I mention it was cool? Fun too.
> 
> 
> -73 de Mike N3LI -
> 
> 
> _______________________________________________
> ATM mailing list http://www.atmlist.net/

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From lugt at xs4all.nl  Fri May 15 16:32:34 2009
From: lugt at xs4all.nl (Marinus van der Lugt)
Date: Fri, 15 May 2009 09:32:34 +0200 (CEST)
Subject: [ATM] silvering reagents and airline baggage
Message-ID: <53764.87.255.50.71.1242372754.squirrel@webmail.xs4all.nl>

With the proper storage (air tight and including a silver protector or a
C02 flooding?), it seems to me that a silver coating would last much
longer than a year. And it could be a very viable solution to the coating
problem that many of us have. (And it keeps the mirror from travelling
-far- and being handled by a third party)
I want to do some testing on that myself, but its low on my priority list.


> On May 14, 2009, at 11:12 AM, Gregg Swanson wrote:
>
>> Ok, I have to ask... Why are we trying to silver a mirror?
>
>
> I don't know about Dominic-Luc's reason, but I had several reasons why
> I silvered my mirror:
>
> 1. I wanted to do an extended star test. I thought my mirror was
> pretty good via the glass only star test, but conditions can affect
> the test.
>
> 2. I was curious to see how a silver surface would last. It turned out
> that with care, it would last over a year. I eventually put a Beral
> coat on it. That year's worth of star testing as well as observing
> convinced me that I was finished figuring. Actually after a month, but
> like I say, I wanted to see how long it would last.
>
> 3. Silvering a mirror is very, very cool. It is another tool in the
> toolkit. I recommend it to anyone who makes a telescope. And I did it
> myself.
>
> 4. Did I mention it was cool? Fun too.
>
>
> -73 de Mike N3LI -
>
>
> _______________________________________________
> ATM mailing list http://www.atmlist.net/
>



From Gregg.Swanson at microsoft.com  Fri May 15 23:16:33 2009
From: Gregg.Swanson at microsoft.com (Gregg Swanson)
Date: Fri, 15 May 2009 07:16:33 -0700
Subject: [ATM] silvering reagents and airline baggage
In-Reply-To: <C8F6EA95-C6E7-4283-BB5C-F051476091FE@psu.edu>
References: <Pine.LNX.4.44.0905141644250.27774-100000@uno.canit.se>
	<D46DD847F1D118479ABF4CBB34B875B212548CEB7C@NA-EXMSG-C113.redmond.corp.microsoft.com>
	<C8F6EA95-C6E7-4283-BB5C-F051476091FE@psu.edu>
Message-ID: <D46DD847F1D118479ABF4CBB34B875B212548CF17E@NA-EXMSG-C113.redmond.corp.microsoft.com>

In my opinion your best reason is #4 --- "cool"; yes, it is very cool.  :)

Gregg

-----Original Message-----
From: atm-bounces at atmlist.net [mailto:atm-bounces at atmlist.net] On Behalf Of Michael Coslo
Sent: Thursday, May 14, 2009 2:37 PM
To: ATM Superheros
Subject: Re: [ATM] silvering reagents and airline baggage


On May 14, 2009, at 11:12 AM, Gregg Swanson wrote:

> Ok, I have to ask... Why are we trying to silver a mirror?


I don't know about Dominic-Luc's reason, but I had several reasons why  
I silvered my mirror:

1. I wanted to do an extended star test. I thought my mirror was  
pretty good via the glass only star test, but conditions can affect  
the test.

2. I was curious to see how a silver surface would last. It turned out  
that with care, it would last over a year. I eventually put a Beral  
coat on it. That year's worth of star testing as well as observing  
convinced me that I was finished figuring. Actually after a month, but  
like I say, I wanted to see how long it would last.

3. Silvering a mirror is very, very cool. It is another tool in the  
toolkit. I recommend it to anyone who makes a telescope. And I did it  
myself.

4. Did I mention it was cool? Fun too.


-73 de Mike N3LI -


_______________________________________________
ATM mailing list http://www.atmlist.net/


From stainless_steel at suddenlink.net  Fri May 15 23:31:52 2009
From: stainless_steel at suddenlink.net (stainless_steel at suddenlink.net)
Date: Fri, 15 May 2009 09:31:52 -0500
Subject: [ATM] ATM: Protective overcoatings for silver films.
Message-ID: <206100C4362A4331BAC1D52F2525EC13@R101>


I seem to remember a formula, given by someone in the old Albert Ingalls 3 
volume (Scientific American) ATM books, for mixing up a batch of a liquid to 
pour on an already silvered mirror to protect it from tarnishing. If I 
remember correctly, it was based on a dilute amyl acetate solution poured 
onto the mirror, with the mirror held at an acutely high angle, so most of 
the stuff runs off, but what is left, after it is dried, is a very thin 
transparent coating that protects the silver, sealing it from air.

Did I imagine this, or can any of you corroborate it?

If so, there are many advantages to silvering at home. If true, it is a very 
elegant innovation by an ATM for the first "enhanced" overcoat for a 
telescope mirror.

DLZ-130



From jkoptic at juno.com  Sat May 16 01:43:40 2009
From: jkoptic at juno.com (Jarvis Krumbein)
Date: Fri, 15 May 2009 09:43:40 -0700
Subject: [ATM] ATM: Protective overcoatings for silver films.
Message-ID: <20090515.094340.3240.0.jkoptic@juno.com>

A good description of this is given in John Strong's "Procedures in
Experimental Physics, published by Prentis-Hall".
Collodion dissolved in ether was used and resulted in very good
protection.  I used this method before aluminizing 
was readily available with very good results.  The secret of getting very
uniform and thin films was to use the method shown and I used 35mm movie
film cans for this.  Just standing the mirror on edge was not nearly as
satisfactory.

Jarvis Krumbein

On Fri, 15 May 2009 09:31:52 -0500 <stainless_steel at suddenlink.net>
writes:
> 
> I seem to remember a formula, given by someone in the old Albert 
> Ingalls 3 
> volume (Scientific American) ATM books, for mixing up a batch of a 
> liquid to 
> pour on an already silvered mirror to protect it from tarnishing. If 
> I 
> remember correctly, it was based on a dilute amyl acetate solution 
> poured 
> onto the mirror, with the mirror held at an acutely high angle, so 
> most of 
> the stuff runs off, but what is left, after it is dried, is a very 
> thin 
> transparent coating that protects the silver, sealing it from air.
> 
> Did I imagine this, or can any of you corroborate it?
> 
> If so, there are many advantages to silvering at home. If true, it 
> is a very 
> elegant innovation by an ATM for the first "enhanced" overcoat for a 
> 
> telescope mirror.
> 
> DLZ-130
> 
> 
> _______________________________________________
> ATM mailing list http://www.atmlist.net/
> 

____________________________________________________________
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From b-hamburger at ya.com  Sat May 16 04:34:34 2009
From: b-hamburger at ya.com (Berthold Hamburger)
Date: Fri, 15 May 2009 21:34:34 +0200
Subject: [ATM] ATM: Protective overcoatings for silver films.
In-Reply-To: <20090515.094340.3240.0.jkoptic@juno.com>
References: <20090515.094340.3240.0.jkoptic@juno.com>
Message-ID: <001901c9d594$2e14f010$8a3ed030$@com>

Do you remember the page number?

Also, considering that collodion USP is already dissolved in ether and
usually peels off once it is dry, I wonder how you keep it on the glass and
even more, how does it not interfere with optical quality?

Berthold Hamburger

-- 
Berthold Hamburger - Cellist/Spain
Email: behambu at artinso.com
http://www.artinso.com
http://www.astro.artinso.com

> -----Original Message-----
> From: atm-bounces at atmlist.net [mailto:atm-bounces at atmlist.net] On Behalf
> Of Jarvis Krumbein
> Sent: viernes, 15 de mayo de 2009 18:44
> To: stainless_steel at suddenlink.net
> Cc: atm at atmlist.net
> Subject: Re: [ATM] ATM: Protective overcoatings for silver films.
> 
> A good description of this is given in John Strong's "Procedures in
> Experimental Physics, published by Prentis-Hall".
> Collodion dissolved in ether was used and resulted in very good
> protection.  I used this method before aluminizing
> was readily available with very good results.  The secret of getting
> very
> uniform and thin films was to use the method shown and I used 35mm movie
> film cans for this.  Just standing the mirror on edge was not nearly as
> satisfactory.
> 
> Jarvis Krumbein
> 
> On Fri, 15 May 2009 09:31:52 -0500 <stainless_steel at suddenlink.net>
> writes:
> >
> > I seem to remember a formula, given by someone in the old Albert
> > Ingalls 3
> > volume (Scientific American) ATM books, for mixing up a batch of a
> > liquid to
> > pour on an already silvered mirror to protect it from tarnishing. If
> > I
> > remember correctly, it was based on a dilute amyl acetate solution
> > poured
> > onto the mirror, with the mirror held at an acutely high angle, so
> > most of
> > the stuff runs off, but what is left, after it is dried, is a very
> > thin
> > transparent coating that protects the silver, sealing it from air.
> >
> > Did I imagine this, or can any of you corroborate it?
> >
> > If so, there are many advantages to silvering at home. If true, it
> > is a very
> > elegant innovation by an ATM for the first "enhanced" overcoat for a
> >
> > telescope mirror.
> >
> > DLZ-130
> >
> >
> > _______________________________________________
> > ATM mailing list http://www.atmlist.net/
> >
> 
> ____________________________________________________________
> Come clean with a brand new shower. Click now!
> http://thirdpartyoffers.juno.com/TGL2141/fc/BLSrjpTGcgyB494cajXmqO3bE8pb
> ZOzii4wwqNqdaCW8dEvDk9MhZoBd32o/
> _______________________________________________
> ATM mailing list http://www.atmlist.net/


From smithersscope at yahoo.com  Sat May 16 05:02:12 2009
From: smithersscope at yahoo.com (Dave Smith)
Date: Fri, 15 May 2009 13:02:12 -0700 (PDT)
Subject: [ATM] trepanning glass, again
Message-ID: <313180.77566.qm@web51805.mail.re2.yahoo.com>

Hey Everyone,
got tired of dealing with other issues and picked up an older project--trepanning glass.
I resurrected my grinding table, bought a $10USD angle grinder and diamond bit disks from harborfreight, and built a jig to hold it over the spinning plate glass. I strung all the power cords over my head on the patio, put on my dual-filter mask, turned on the hose and let her rip.

Interesting, indeed.

The table is spinning about 30rpm (24" turntable); the grinder is doing 4000rpm+.
Before it took me at least an hour and a half with a homemade circle cutting jig and 60 grit to trepan a disk from 1/2 inch plate glass, and it would get really hot (glass and motor).
With the new setup.....5 minutes. 
Cuts glass like a carbide tipped blade on oak.
I was just tinkering with 5 and 6 inch (130-150mm) disks last night. The edges have lots of little clam shell fractures/chips. The backside more so than the front. No big deal--most will disappear with a good beveling. If I took my time to improve my jig and eliminate vibration, I suspect I could smooth the operation considerably.
But still, what an amazing improvement! Too cool!

I was super careful and didn't have any problems, but this is freaking dangerous.

1. water all over the ground, electrical lines up high (GFP circuits a must).
2. potential for jamming up and spewing glass shards (large and small) is high.
3. glass dust is generated no matter how much water I spray at the moving disk grinder blade--the grinder is just spinning too fast. (table speed is good though)
4. there's a large swath or path of glass removed using this method (probably 3/4 inch/20mm). that's a LOT of glass dust.
5. the profile of the glass edge is flat; trepanning before always gave me a conical figure--narrow on top, fat on bottom). These are truly cylindrical.
6. two ~6 inch disks and the blade shows NO sign of wear.

Thought someone might find the info interesting or useful.
dumpster dave




      

From jkoptic at juno.com  Sat May 16 06:03:23 2009
From: jkoptic at juno.com (Jarvis Krumbein)
Date: Fri, 15 May 2009 14:03:23 -0700
Subject: [ATM] ATM: Protective overcoatings for silver films.
Message-ID: <20090515.140323.2100.0.jkoptic@juno.com>

Berthold, pages 158 and 159 in the chapter on Evaporation and Sputtering
in John Strong's "Procedures in Experimental Physics, published by
Prentis-Hall".  It's been close to fifty years since I last did this but
I do remember that the collodion/ether mix had to be very thin for good
results.  I'm sure that the current collodion USP will have to be thinned
quite a bit with more ether.  The film I got was so thin you couldn't
really tell it was there.  The silver coatings did stand up fairly well
and a year or more was to be expected.  I was never able to see any
difference between the coated and uncoated mirrors.

On Fri, 15 May 2009 21:34:34 +0200 "Berthold Hamburger"
<b-hamburger at ya.com> writes:
> Do you remember the page number?
> 
> Also, considering that collodion USP is already dissolved in ether 
> and
> usually peels off once it is dry, I wonder how you keep it on the 
> glass and
> even more, how does it not interfere with optical quality?
> 
> Berthold Hamburger
> 
> -- 
> Berthold Hamburger - Cellist/Spain
> Email: behambu at artinso.com
> http://www.artinso.com
> http://www.astro.artinso.com
> 
> > -----Original Message-----
> > From: atm-bounces at atmlist.net [mailto:atm-bounces at atmlist.net] On 
> Behalf
> > Of Jarvis Krumbein
> > Sent: viernes, 15 de mayo de 2009 18:44
> > To: stainless_steel at suddenlink.net
> > Cc: atm at atmlist.net
> > Subject: Re: [ATM] ATM: Protective overcoatings for silver films.
> > 
> > A good description of this is given in John Strong's "Procedures 
> in
> > Experimental Physics, published by Prentis-Hall".
> > Collodion dissolved in ether was used and resulted in very good
> > protection.  I used this method before aluminizing
> > was readily available with very good results.  The secret of 
> getting
> > very
> > uniform and thin films was to use the method shown and I used 35mm 
> movie
> > film cans for this.  Just standing the mirror on edge was not 
> nearly as
> > satisfactory.
> > 
> > Jarvis Krumbein
> > 
> >
____________________________________________________________
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From smithersscope at yahoo.com  Sat May 16 06:40:46 2009
From: smithersscope at yahoo.com (Dave Smith)
Date: Fri, 15 May 2009 14:40:46 -0700 (PDT)
Subject: [ATM] trepanning glass, again
Message-ID: <40718.71963.qm@web51810.mail.re2.yahoo.com>

Hi Peter,
All good questions!
#5-6. Not only was the wife home, but she was hosting some "stampin up" party in the kitchen 25 feet away!
She said it was loud, but not as loud as a room full of women! (ha!) I did not need or use ear protection--wasn't that loud. (I did see sparks occassionally!? Is glass really tougher than steel!? (smile))

1. I used 4 inch long 1/4" ply strips and some cut up innertube and sandwiched/pinched the two glass pieces in place. Drove wood screws thru the ply and rubber right into pre-existing holes in my turntable as best I could, as close to the lower glass square as possible. Sort of like clamps...flat enough to clear the grinder as the turntable went around. I used a sheet of? 3/8 inch "dummy" glass underneath the piece I was cutting.
2. The grinder was mounted above the turntable pointing blade down, blade tangential to the circle I cut.
3. Yes, cutting with as much water as I could spray/drip on the glass and blade without hosing down the grinder. The table/patio slopes slightly, so I had the table positioned to drain into the grass at the edge of the concrete slab--not really very messy. The damage was over QUICK!

4. The jig I built allowed me to ease the grinder down as it ate away at the glass. I held the grinder near the kill switch most of the time and "gently" controlled the descent. 
My comments earlier about building a better jig would include some sort of rigid mount and a way to adjust depth--as with a screw I would think.


Y'all don't EVEN try this without some sort of lung protection! Even when the blade was nearly through the glass and practically submerged, it was still kicking up clouds of glass dust.

Thanks,
dave



--- On Fri, 5/15/09, Peter De Baan <pdebaan at hotmail.com> wrote:

From: Peter De Baan <pdebaan at hotmail.com>
Subject: RE: [ATM] trepanning glass, again
To: smithersscope at yahoo.com
Date: Friday, May 15, 2009, 1:46 PM




#yiv1515746557 .hmmessage P
{
margin:0px;padding:0px;}
#yiv1515746557 {
font-size:10pt;font-family:Verdana;}

Hi Dave,
that sounds very interesting, and leave some questions,
1 how did you fasten the glass ont the turn table?
2 where you cutting with the diamond blade upwards against the turning glass?
3 where you weth cutting?
4 did you control the cutting dept with a screw?

5 did you need ear-sound muffs
6 was your wife home?
Thanks Dave,
Peter


> Date: Fri, 15 May 2009 13:02:12 -0700
> From: smithersscope at yahoo.com
> To: atm at atmlist.net
> Subject: [ATM] trepanning glass, again
> 
> Hey Everyone,
> got tired of dealing with other issues and picked up an older project--trepanning glass.
> I resurrected my grinding table, bought a $10USD angle grinder and diamond bit disks from harborfreight, and built a jig to hold it over the spinning plate glass. I strung all the power cords over my head on the patio, put on my dual-filter mask, turned on the hose and let her rip.
> 
> Interesting, indeed.
> 
> The table is spinning about 30rpm (24" turntable); the grinder is doing 4000rpm+.
> Before it took me at least an hour and a half with a homemade circle cutting jig and 60 grit to trepan a disk from 1/2 inch plate glass, and it would get really hot (glass and motor).
> With the new setup.....5 minutes. 
> Cuts glass like a carbide tipped blade on oak.
> I was just tinkering with 5 and 6 inch (130-150mm) disks last night. The edges have lots of little clam shell fractures/chips. The backside more so than the front. No big deal--most will disappear with a good beveling. If I took my time to improve my jig and eliminate vibration, I suspect I could smooth the operation considerably.
> But still, what an amazing improvement! Too cool!
> 
> I was super careful and didn't have any problems, but this is freaking dangerous.
> 
> 1. water all over the ground, electrical lines up high (GFP circuits a must).
> 2. potential for jamming up and spewing glass shards (large and small) is high.
> 3. glass dust is generated no matter how much water I spray at the moving disk grinder blade--the grinder is just spinning too fast. (table speed is good though)
> 4. there's a large swath or path of glass removed using this method (probably 3/4 inch/20mm). that's a LOT of glass dust.
> 5. the profile of the glass edge is flat; trepanning before always gave me a conical figure--narrow on top, fat on bottom). These are truly cylindrical.
> 6. two ~6 inch disks and the blade shows NO sign of wear.
> 
> Thought someone might find the info interesting or useful.
> dumpster dave
> 
> 
> 
> 
>       
> _______________________________________________
> ATM mailing list http://www.atmlist.net/

Windows Live?: Keep your life in sync. Check it out. 



      

From wkitty42 at windstream.net  Sat May 16 06:46:43 2009
From: wkitty42 at windstream.net (waldo kitty)
Date: Fri, 15 May 2009 17:46:43 -0400
Subject: [ATM] trepanning glass, again
In-Reply-To: <40718.71963.qm@web51810.mail.re2.yahoo.com>
References: <40718.71963.qm@web51810.mail.re2.yahoo.com>
Message-ID: <4A0DE2C3.3090206@windstream.net>

Dave Smith wrote:
> Hi Peter,
> All good questions!

wow, i haven't even seen peter's post arrive on the list yet :/
i just got your first one, dave and then this one not 5 minutes later...

-- 
        _\/
       (@@)                      Waldo Kitty, Waldo's Place USA
__ooO_( )_Ooo_____________________ telnet://bbs.wpusa.dynip.com
_|_____|_____|_____|_____|_____|_____ http://www.wpusa.dynip.com
____|_____|_____|_____|_____|_____|____ ftp://ftp.wpusa.dynip.com
_|_Eat_SPAM_to_email_me!_YUM!__|_____ wkitty42 -at- windstream.net

From pdebaan at hotmail.com  Sat May 16 08:45:10 2009
From: pdebaan at hotmail.com (Peter De Baan)
Date: Fri, 15 May 2009 23:45:10 +0000
Subject: [ATM] trepanning glass, again
In-Reply-To: <4A0DE2C3.3090206@windstream.net>
References: <40718.71963.qm@web51810.mail.re2.yahoo.com>
	<4A0DE2C3.3090206@windstream.net>
Message-ID: <BLU137-W296D06BD622CB0EEF3BFC8B25F0@phx.gbl>


Sorry Waldo, 

I apparently pushed the wrong button,

 

Hi Dave,
that sounds very interesting, and leave some questions,
1 how did you fasten the glass ont the turn table?
2 where you cutting with the diamond blade upwards against the turning glass?
3 where you weth cutting?
4 did you control the cutting dept with a screw 

5 did you need ear-sound muffs
6 was your wife home?
Thanks Dave,
Peter

 
> Date: Fri, 15 May 2009 17:46:43 -0400
> From: wkitty42 at windstream.net
> To: atm at atmlist.net
> Subject: Re: [ATM] trepanning glass, again
> 
> Dave Smith wrote:
> > Hi Peter,
> > All good questions!
> 
> wow, i haven't even seen peter's post arrive on the list yet :/
> i just got your first one, dave and then this one not 5 minutes later...
> 
> -- 
> _\/
> (@@) Waldo Kitty, Waldo's Place USA
> __ooO_( )_Ooo_____________________ telnet://bbs.wpusa.dynip.com
> _|_____|_____|_____|_____|_____|_____ http://www.wpusa.dynip.com
> ____|_____|_____|_____|_____|_____|____ ftp://ftp.wpusa.dynip.com
> _|_Eat_SPAM_to_email_me!_YUM!__|_____ wkitty42 -at- windstream.net
> _______________________________________________
> ATM mailing list http://www.atmlist.net/

_________________________________________________________________
Windows Live?: Keep your life in sync.
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From arjan.te.marvelde at hetnet.nl  Sat May 16 14:41:21 2009
From: arjan.te.marvelde at hetnet.nl (Arjan te Marvelde (hetnet))
Date: Sat, 16 May 2009 07:41:21 +0200
Subject: [ATM] ATM: Protective overcoatings for silver films.
In-Reply-To: <mailman.1040.1242423649.7676.atm@atmlist.net>
References: <mailman.1040.1242423649.7676.atm@atmlist.net>
Message-ID: <4A0E5201.2030704@hetnet.nl>

I've used Poly Urethane dissolved in Amyl Acetate to glue glass fibers 
into a V-groove etched in a silicon wafer. As far as I can remember, the 
amylacetate evaporated completely, leaving only the cured PU.

For related experiments, I had to spin-coat the Si wafer with a 1/4 wave 
layer of photoresist; I suppose for optimum reflection you would need 
something in the same order of thickness. It apeared to be very hard to 
obtain a layer that thin, with sufficiently homogeneous thickness, using 
this technique.

Maybe evaporation of a thin solution will be better in this respect?
So, I'd be very interested in the technique described by Strong. Jarvis, 
I don't have this book: could you perhaps give a brief summary of what 
you did?

Thanks,
   Arjan
 
> I seem to remember a formula, given by someone in the old Albert Ingalls 3 
> volume (Scientific American) ATM books, for mixing up a batch of a liquid to 
> pour on an already silvered mirror to protect it from tarnishing. If I 
> remember correctly, it was based on a dilute amyl acetate solution poured 
> onto the mirror, with the mirror held at an acutely high angle, so most of 
> the stuff runs off, but what is left, after it is dried, is a very thin 
> transparent coating that protects the silver, sealing it from air.
>
>   

From dlwebb at canit.se  Sat May 16 15:34:46 2009
From: dlwebb at canit.se (Dominic-Luc Webb)
Date: Sat, 16 May 2009 08:34:46 +0200 (MET DST)
Subject: [ATM] silvering in the 9/11 epoch
Message-ID: <Pine.LNX.4.44.0905160800210.20228-100000@uno.canit.se>


Specifically, Peacock Laboratories, Inc., which must have
a lot of experience with silvering products, offers/recommends
the following components, effectively a "kit":

#93 Sensitizer 1 4 Oz. Bottle 16.20
HE-400 S Silver Solution 1 4 Oz. Bottle 68.00
HE-400 RReducer Solution 1 4 Oz. Bottle 67.00
Spec. pkg. req. by Federal Law 20.00
Shipping and Insurance Charges 198.30

Total: $369.50

Charges when reaching Sweden, multiply by 1.25 = $461.88 (3695 SEK)

I have yet to determine if Swedish customs will allow a
private person to take possession of these chemicals. Such
problems with other chemicals has been an issue in the past.

Do-able for most people with a job, but it is quite interesting
how money burns in this post 9/11 world. As far as I know, the
only special ingredient that is not easy/cheap to find is the
silver nitrate. Shipping and insurance and then taxes on that is
by far the biggest cost. Therefore, buying these things from a
local source and doing the work there is far more cost effective
than trying to ship it overseas. In fact, price to end up with
this in Sweden is pretty close to what I paid for my round
trip plane ticket to the States.

I will arrive in Berkeley, CA Monday. I will see what can be
done while I am there.

Dominic


From atmer at flash.net  Sat May 16 16:34:17 2009
From: atmer at flash.net (Anthony Stillman)
Date: Sat, 16 May 2009 00:34:17 -0700 (PDT)
Subject: [ATM] silvering in the 9/11 epoch
In-Reply-To: <Pine.LNX.4.44.0905160800210.20228-100000@uno.canit.se>
References: <Pine.LNX.4.44.0905160800210.20228-100000@uno.canit.se>
Message-ID: <524985.48611.qm@web82008.mail.mud.yahoo.com>


Silver nitrate.

As I recall one need only dissolve pure silver in hot nitric acid and let the solution dry.  Not for sure certain I checked my 112 year old book of recipes.  While it presents in detail how to slaughter a hen and how to make nitro-glycerin as well as various fulminates, silver nitrate, being readily available, didn't warrant discussion.  For that I had to surf the net.  Let the solution dry in the dark.

Its bad enough that chemicals that could be store bought 30 years ago now require a background check and a sample of skin, but that a majority of Americans actually believe that these hindrances make them safer, that's down right scary.

Anthony




----- Original Message ----
From: Dominic-Luc Webb <dlwebb at canit.se>
To: ATM Superheros <atm at atmlist.net>
Sent: Friday, May 15, 2009 11:34:46 PM
Subject: [ATM] silvering in the 9/11 epoch


Specifically, Peacock Laboratories, Inc., which must have
a lot of experience with silvering products, offers/recommends
the following components, effectively a "kit":

#93 Sensitizer 1 4 Oz. Bottle 16.20
HE-400 S Silver Solution 1 4 Oz. Bottle 68.00
HE-400 RReducer Solution 1 4 Oz. Bottle 67.00
Spec. pkg. req. by Federal Law 20.00
Shipping and Insurance Charges 198.30

Total: $369.50

Charges when reaching Sweden, multiply by 1.25 = $461.88 (3695 SEK)

I have yet to determine if Swedish customs will allow a
private person to take possession of these chemicals. Such
problems with other chemicals has been an issue in the past.

Do-able for most people with a job, but it is quite interesting
how money burns in this post 9/11 world. As far as I know, the
only special ingredient that is not easy/cheap to find is the
silver nitrate. Shipping and insurance and then taxes on that is
by far the biggest cost. Therefore, buying these things from a
local source and doing the work there is far more cost effective
than trying to ship it overseas. In fact, price to end up with
this in Sweden is pretty close to what I paid for my round
trip plane ticket to the States.

I will arrive in Berkeley, CA Monday. I will see what can be
done while I am there.

Dominic

_______________________________________________
ATM mailing list http://www.atmlist.net/


From dlwebb at canit.se  Sat May 16 18:20:35 2009
From: dlwebb at canit.se (Dominic-Luc Webb)
Date: Sat, 16 May 2009 11:20:35 +0200 (MET DST)
Subject: [ATM] silvering in the 9/11 epoch
In-Reply-To: <524985.48611.qm@web82008.mail.mud.yahoo.com>
Message-ID: <Pine.LNX.4.44.0905161118230.15723-100000@uno.canit.se>

On Sat, 16 May 2009, Anthony Stillman wrote:

> Silver nitrate.
>
> As I recall one need only dissolve pure silver in hot nitric acid...

I would much prefer trying to buy/transport silver nitrate than
nitric acid. I do not think anyone would sell me nitric acid in
Sweden. I actually did buy this in pre-9/11 Berkeley.

Dominic



From gfbrandenburg at yahoo.com  Sat May 16 21:47:02 2009
From: gfbrandenburg at yahoo.com (Guy Brandenburg)
Date: Sat, 16 May 2009 05:47:02 -0700 (PDT)
Subject: [ATM] trepanning glass, again
Message-ID: <879643.93959.qm@web111508.mail.gq1.yahoo.com>

Last summer I did some hogging out - not trepanning - with a similar setup, but instead of electric tools, which I thought was WAY too dangerous, I used an air compressor and grinder. I made a long pendulum with its fulcrum on a 2nd floor fire escape, set to the correct radius of curvature, fastened the grinder to the end of the pendulum immersed the mirror in a bucket of water, and went to work with lots of eye, ear, and lung protection. The hogging out was very fast. No dust, but I got splattered with lots of water.


Guy Brandenburg, Washington, DC
My home page on astronomy, mathematics, education:
http://home.earthlink.net/~gfbranden/GFB_Home_Page.html
or else 
http://tinyurl.com/r6fh2

=============================
"Education isn't rocket science. It's much, much harder."
(Author unknown)


--- On Fri, 5/15/09, Dave Smith <smithersscope at yahoo.com> wrote:

From: Dave Smith <smithersscope at yahoo.com>
Subject: Re: [ATM] trepanning glass, again
To: "Peter De Baan" <pdebaan at hotmail.com>, "ATMLIST" <atm at atmlist.net>
Date: Friday, May 15, 2009, 5:40 PM

Hi Peter,
All good questions!
#5-6. Not only was the wife home, but she was hosting some "stampin up" party in the kitchen 25 feet away!
She said it was loud, but not as loud as a room full of women! (ha!) I did not need or use ear protection--wasn't that loud. (I did see sparks occassionally!? Is glass really tougher than steel!? (smile))

1. I used 4 inch long 1/4" ply strips and some cut up innertube and sandwiched/pinched the two glass pieces in place. Drove wood screws thru the ply and rubber right into pre-existing holes in my turntable as best I could, as close to the lower glass square as possible. Sort of like clamps...flat enough to clear the grinder as the turntable went around. I used a sheet of? 3/8 inch "dummy" glass underneath the piece I was cutting.
2. The grinder was mounted above the turntable pointing blade down, blade tangential to the circle I cut.
3. Yes, cutting with as much water as I could spray/drip on the glass and blade without hosing down the grinder. The table/patio slopes slightly, so I had the table positioned to drain into the grass at the edge of the concrete slab--not really very messy. The damage was over QUICK!

4. The jig I built allowed me to ease the grinder down as it ate away at the glass. I held the grinder near the kill switch most of the time and "gently" controlled the descent. 
My comments earlier about building a better jig would include some sort of rigid mount and a way to adjust depth--as with a screw I would think.


Y'all don't EVEN try this without some sort of lung protection! Even when the blade was nearly through the glass and practically submerged, it was still kicking up clouds of glass dust.

Thanks,
dave



--- On Fri, 5/15/09, Peter De Baan <pdebaan at hotmail.com> wrote:

From: Peter De Baan <pdebaan at hotmail.com>
Subject: RE: [ATM] trepanning glass, again
To: smithersscope at yahoo.com
Date: Friday, May 15, 2009, 1:46 PM




#yiv1515746557 .hmmessage P
{
margin:0px;padding:0px;}
#yiv1515746557 {
font-size:10pt;font-family:Verdana;}

Hi Dave,
that sounds very interesting, and leave some questions,
1 how did you fasten the glass ont the turn table?
2 where you cutting with the diamond blade upwards against the turning glass?
3 where you weth cutting?
4 did you control the cutting dept with a screw?

5 did you need ear-sound muffs
6 was your wife home?
Thanks Dave,
Peter


> Date: Fri, 15 May 2009 13:02:12 -0700
> From: smithersscope at yahoo.com
> To: atm at atmlist.net
> Subject: [ATM] trepanning glass, again
> 
> Hey Everyone,
> got tired of dealing with other issues and picked up an older project--trepanning glass.
> I resurrected my grinding table, bought a $10USD angle grinder and diamond bit disks from harborfreight, and built a jig to hold it over the spinning plate glass. I strung all the power cords over my head on the patio, put on my dual-filter mask, turned on the hose and let her rip.
> 
> Interesting, indeed.
> 
> The table is spinning about 30rpm (24" turntable); the grinder is doing 4000rpm+.
> Before it took me at least an hour and a half with a homemade circle cutting jig and 60 grit to trepan a disk from 1/2 inch plate glass, and it would get really hot (glass and motor).
> With the new setup.....5 minutes. 
> Cuts glass like a carbide tipped blade on oak.
> I was just tinkering with 5 and 6 inch (130-150mm) disks last night. The edges have lots of little clam shell fractures/chips. The backside more so than the front. No big deal--most will disappear with a good beveling. If I took my time to improve my jig and eliminate vibration, I suspect I could smooth the operation considerably.
> But still, what an amazing improvement! Too cool!
> 
> I was super careful and didn't have any problems, but this is freaking dangerous.
> 
> 1. water all over the ground, electrical lines up high (GFP circuits a must).
> 2. potential for jamming up and spewing glass shards (large and small) is high.
> 3. glass dust is generated no matter how much water I spray at the moving disk grinder blade--the grinder is just spinning too fast. (table speed is good though)
> 4. there's a large swath or path of glass removed using this method (probably 3/4 inch/20mm). that's a LOT of glass dust.
> 5. the profile of the glass edge is flat; trepanning before always gave me a conical figure--narrow on top, fat on bottom). These are truly cylindrical.
> 6. two ~6 inch disks and the blade shows NO sign of wear.
> 
> Thought someone might find the info interesting or useful.
> dumpster dave
> 
> 
> 
> 
>? ? ???
> _______________________________________________
> ATM mailing list http://www.atmlist.net/

Windows Live?: Keep your life in sync. Check it out. 



? ? ? 
_______________________________________________
ATM mailing list http://www.atmlist.net/


      

From atmer at flash.net  Sun May 17 17:39:25 2009
From: atmer at flash.net (Anthony Stillman)
Date: Sun, 17 May 2009 01:39:25 -0700 (PDT)
Subject: [ATM] silvering in the 9/11 epoch
In-Reply-To: <Pine.LNX.4.44.0905161118230.15723-100000@uno.canit.se>
Message-ID: <453592.5739.qm@web82008.mail.mud.yahoo.com>


Sadly Bryant Labs got shut down by the DEA.  They had good reason.

I didn't know how to make nitric acid so I checked the net.  Potassium nitrate and sulfuric acid along with distillation procedure.  When I got to the part about letting the red cloud dissipate I decided it was a bad idea.  That red cloud is nitric oxide. (NOT nitrous) It converts to nitric acid in the lungs thus liquifying them.  I've had the opportunity to see this pretty red-brown cloud from the other side of a hood.  Even then it was scary.

Silver nitrate or nitric acid shouldn't be that difficult to get, even in Sweden.  I use nitric acid to etch silver jewelry.  Sweden's principal export seems to be tall buxom blonds and I suspect they're given silver jewelry when they're very young.  After that it's probably only platinum and gold.

Googling "chemical supplies" "silver nitrate" and "Sweden" got 60 hits.  But I can't read the gibberi-opps I mean Swedish.

Perhaps a list of suppliers for ATM type chemicals can be put together for every country. Along with what hurdles need to be overcome to buy things like di-hydrogen oxide.  

Anthony






--- On Sat, 5/16/09, Dominic-Luc Webb <dlwebb at canit.se> wrote:

> From: Dominic-Luc Webb <dlwebb at canit.se>
> Subject: Re: [ATM] silvering in the 9/11 epoch
> To: "ATM Superheros" <atm at atmlist.net>
> Date: Saturday, May 16, 2009, 2:20 AM
> On Sat, 16 May 2009, Anthony Stillman wrote:
> 
> > Silver nitrate.
> >
> > As I recall one need only dissolve pure silver in hot
> nitric acid...
> 
> I would much prefer trying to buy/transport silver nitrate
> than
> nitric acid. I do not think anyone would sell me nitric
> acid in
> Sweden. I actually did buy this in pre-9/11 Berkeley.
> 
> Dominic
> 
> 
> _______________________________________________
> ATM mailing list http://www.atmlist.net/

From jfj at telia.com  Sun May 17 19:52:29 2009
From: jfj at telia.com (Joakim F Johansson)
Date: Sun, 17 May 2009 12:52:29 +0200
Subject: [ATM] silvering in the 9/11 epoch
In-Reply-To: <453592.5739.qm@web82008.mail.mud.yahoo.com>
Message-ID: <FC8FF02872244535A17B6C8CF68A1810@NyCOMPAQ>

>>Silver nitrate or nitric acid shouldn't be that difficult to get, even in
Sweden.

Well, that depends... If you are a bona fide user it is easy. The
authorities in Sweden are not as paranoid about making explosives out of the
stuff as they are about the environmental issues. In principle, all handling
of non-household chemicals is subject to quite tough rules.

Hence, chemical supply companies would not sell to anyone that could not
prove that they can take care of the chemicals in a safe an environmentally
sound way, i.e. they do not sell to amateurs. 

Were it possible to acquire e.g. silver nitrate, you have a problem to
dispose of any left-overs. If you dump it into the sink and they find out,
you will get a hefty fine. Silver is a toxic to all kinds of organisms and
would thus wreak havoc in the waste water cleaning process. You might be
able to dump it in a labled bottle at the local recycling station, but any
environmentally correct disposal would be costly.

///Joakim Johansson


From vladimir.galogaza1 at zg.t-com.hr  Sun May 17 23:58:15 2009
From: vladimir.galogaza1 at zg.t-com.hr (Vladimir Galogaza)
Date: Sun, 17 May 2009 16:58:15 +0200
Subject: [ATM] silvering in the 9/11 epoch
References: <FC8FF02872244535A17B6C8CF68A1810@NyCOMPAQ>
Message-ID: <AE31DAFC32304FBF801EB9A85CC305AD@piv555a133b59e>

The post of Joakim Johansson about problems with silvering
is one of the best I saw from the  "warning department".
We ATMs, being from all sorts of occupation and experience levels,
need very much this kind of assistance well written and  supported with
facts.

Thanks Joakim.
Regards
Vladimir.

From jeffrowe at austin.rr.com  Mon May 18 02:12:56 2009
From: jeffrowe at austin.rr.com (Jeff Rowe)
Date: Sun, 17 May 2009 12:12:56 -0500
Subject: [ATM] silvering in the 9/11 epoch
In-Reply-To: <453592.5739.qm@web82008.mail.mud.yahoo.com>
References: <453592.5739.qm@web82008.mail.mud.yahoo.com>
Message-ID: <4A104598.50509@austin.rr.com>

Friends;
An ATMer in Florida, James Lerch, has made his own silver nitrate. He 
posted warnings about the EXTREME DANGERS,  involved in the process.  
Parts per billion of the "cloud", can lead to death. I  combined nitric 
acid with silver in lab glassware once, and as soon, as I saw the 
red-brown smoke, realized, it was a horrendously bad idea. Fortunately I 
had no foul consequences; yes I did make silver nitrate.  Do a search on 
Jame's work prior to trying this potentially lethel stunt. JMHO  Think 
fume hood,  or the great outdoors, as well as all the other 
protections.  In the words of Dirty Harry, "Are you feelin lucky 
today...?" This is not for the weak of heart, or unprepared, unless you 
want a Darwin Award.
Best
Jeff Rowe

Anthony Stillman wrote:

>Sadly Bryant Labs got shut down by the DEA.  They had good reason.
>
>I didn't know how to make nitric acid so I checked the net.  Potassium nitrate and sulfuric acid along with distillation procedure.  When I got to the part about letting the red cloud dissipate I decided it was a bad idea.  That red cloud is nitric oxide. (NOT nitrous) It converts to nitric acid in the lungs thus liquifying them.  I've had the opportunity to see this pretty red-brown cloud from the other side of a hood.  Even then it was scary.
>
>Silver nitrate or nitric acid shouldn't be that difficult to get, even in Sweden.  I use nitric acid to etch silver jewelry.  Sweden's principal export seems to be tall buxom blonds and I suspect they're given silver jewelry when they're very young.  After that it's probably only platinum and gold.
>
>Googling "chemical supplies" "silver nitrate" and "Sweden" got 60 hits.  But I can't read the gibberi-opps I mean Swedish.
>
>Perhaps a list of suppliers for ATM type chemicals can be put together for every country. Along with what hurdles need to be overcome to buy things like di-hydrogen oxide.  
>
>Anthony
>
>
>
>
>
>
>--- On Sat, 5/16/09, Dominic-Luc Webb <dlwebb at canit.se> wrote:
>
>  
>
>>From: Dominic-Luc Webb <dlwebb at canit.se>
>>Subject: Re: [ATM] silvering in the 9/11 epoch
>>To: "ATM Superheros" <atm at atmlist.net>
>>Date: Saturday, May 16, 2009, 2:20 AM
>>On Sat, 16 May 2009, Anthony Stillman wrote:
>>
>>    
>>
>>>Silver nitrate.
>>>
>>>As I recall one need only dissolve pure silver in hot
>>>      
>>>
>>nitric acid...
>>
>>I would much prefer trying to buy/transport silver nitrate
>>than
>>nitric acid. I do not think anyone would sell me nitric
>>acid in
>>Sweden. I actually did buy this in pre-9/11 Berkeley.
>>
>>Dominic
>>
>>
>>_______________________________________________
>>ATM mailing list http://www.atmlist.net/
>>    
>>
>_______________________________________________
>ATM mailing list http://www.atmlist.net/
>
>  
>

From richard at foucault.co.uk  Mon May 18 02:56:04 2009
From: richard at foucault.co.uk (Richard in the UK)
Date: Sun, 17 May 2009 18:56:04 +0100
Subject: [ATM] silvering in the 9/11 epoch
In-Reply-To: <4A104598.50509@austin.rr.com>
References: <453592.5739.qm@web82008.mail.mud.yahoo.com>
	<4A104598.50509@austin.rr.com>
Message-ID: <1978611733.20090517185604@foucault.co.uk>

Hello Jeff,

Sunday, May 17, 2009, 6:12:56 PM, you wrote:

> Parts per billion of the "cloud", can lead to death.

Nitric Oxide is a pulmonary vasodilator, used at concentrations up to
800ppm as the trade named pharmaceutical Inomax.

However, IS IT Nitric Oxide that is given off?. I think it is more
likely to be Nitrogen Dioxide (NO2) which really IS dangerous. So, a
cloud of NO2 could kill you, a cloud of NO is nowhere near as
dangerous.

Ag + 2HNO3 --> AgNO3 + NO2 + H2O

-- 
Best regards,
 Richard in the UK


From richard at foucault.co.uk  Mon May 18 02:46:37 2009
From: richard at foucault.co.uk (Richard in the UK)
Date: Sun, 17 May 2009 18:46:37 +0100
Subject: [ATM] silvering in the 9/11 epoch
In-Reply-To: <453592.5739.qm@web82008.mail.mud.yahoo.com>
References: <Pine.LNX.4.44.0905161118230.15723-100000@uno.canit.se>
	<453592.5739.qm@web82008.mail.mud.yahoo.com>
Message-ID: <1602056675.20090517184637@foucault.co.uk>

Hello Anthony,

Sunday, May 17, 2009, 9:39:25 AM, you wrote:

> That red cloud is nitric
> oxide. (NOT nitrous) It converts to nitric acid in the lungs thus
> liquifying them.

Are you sure it is Nitric Oxide (NO) ?

-- 
Best regards,
 Richard in the UK


From dlwebb at canit.se  Mon May 18 03:28:15 2009
From: dlwebb at canit.se (Dominic-Luc Webb)
Date: Sun, 17 May 2009 20:28:15 +0200 (MET DST)
Subject: [ATM] silvering in the 9/11 epoch
In-Reply-To: <453592.5739.qm@web82008.mail.mud.yahoo.com>
Message-ID: <Pine.LNX.4.44.0905172020010.10849-100000@uno.canit.se>

On Sun, 17 May 2009, Anthony Stillman wrote:

> Silver nitrate or nitric acid shouldn't be that difficult to get, even in Sweden.  I use nitric acid to etch silver jewelry.  Sweden's principal export seems to be tall buxom blonds and I suspect they're given silver jewelry when they're very young.  After that it's probably only platinum and gold.
> Anthony

Joakim's remarks are in line with my experience, although, specific
environmental issues were never discussed. Fortunately my chemistry
background came to the rescue. I had to go through an interview
with the customs people. After that, I was allowed to bring these
very hazardous chemicals into the country. These horrible
compounds were purified amino acids!!!

However, there is a lot of interest here in making jewelry
from silver. I have already contacted a couple adult
schools that teach such things to get some tips. So far,
lot's of people working silver jewelry, pretty much
exclusively women (not sure why), but not one trying to
make mirrors. I may visit one of the courses to get some
tips.

Dominic


From junkwheaton at gmail.com  Mon May 18 10:05:21 2009
From: junkwheaton at gmail.com (Bill Wheaton)
Date: Sun, 17 May 2009 21:05:21 -0400
Subject: [ATM] [Fwd: Re: Polyurethane tiles]
In-Reply-To: <004f01c9d344$3848c5e0$8f78fea9@amd>
References: <Pine.LNX.4.44.0905110954040.28033-100000@uno.canit.se>
	<C89B6E6A-F156-445A-8042-DB026D617009@psu.edu>
	<004f01c9d344$3848c5e0$8f78fea9@amd>
Message-ID: <cd0f54500905171805r4852a038odd5fab85174b8420@mail.gmail.com>

I'm surprised Davey hasn't piped up, but he recommends concrete/tile tools.
 I tried it on his instruction and it worked fine with his method for my
12.5"  Check my blog for plenty of pictures, videos etc. as I document my
project. http://pythiashat.blogspot.com.  or my youtube page:
http://www.youtube.com/user/tabhorian
Also Francis O'Reilly has a several videos dedicated to making a lap with
dental stone starting here: http://www.youtube.com/watch?v=SZpov8cjDic
As Bob says, use the really hard floor tiles.  Mine were in a 12"x12" sheet
I found at a big box store.  (soak in water to get rid of the paper
backing... see the pics.)

I really recommend making videos and sharing them.  It's not hard at all,
and we can all benefit.  To not do them leaves our hobby in the dark ages.
 You can find out how do anything from knitting to rocketry to fun with
thermite and propane tanks to mag lev to aluminum casting and telescope
making.

-Bill Wheaton

On Tue, May 12, 2009 at 4:56 PM, Bob May <rmay at nethere.com> wrote:

> Please understand that there are two types of tiles sold for
> houses, etc.
> There is the wall tile.  This is a soft tile with a coating on
> the one surface so that it looks pretty.  Not good for making
> tile tools as they are as soft as, if not softer than, the stone
> used to hold them.
> There is also the floor tile.  These are intended to be walked on
> and thus are a lot harder than the wall tiles.  These are usually
> done in smaller sizes and are of a single color and need to have
> wax applied to get a polished surface.  They also tend to look
> like they were cast in a closed mold rather than the wall tile
> that looks like it got painted on a half mold.
> I'll note that you can also use glass cut up for tiles as well as
> hard stones to do the job.  I'm mostly using glass for tools now
> as the glass is readily available.
> Bob May
>
> rmay at nethere.com
> http: slash /nav.to slash bobmay
> http: slash /bobmay dot astronomy.net
>
>
> _______________________________________________
> ATM mailing list http://www.atmlist.net/
>

From junkwheaton at gmail.com  Mon May 18 10:23:22 2009
From: junkwheaton at gmail.com (Bill Wheaton)
Date: Sun, 17 May 2009 21:23:22 -0400
Subject: [ATM] ATM:ATM: reply, forward Re: Polyurethane tiles
In-Reply-To: <E0048BC4F79D47FDA7B508F2C0F88464@R101>
References: <E0048BC4F79D47FDA7B508F2C0F88464@R101>
Message-ID: <cd0f54500905171823p7d372398u537ddf292575474e@mail.gmail.com>

I gotta second Davey's method.  Hard to find the hex tiles anymore so I used
square ones.
One thing I will say... between grits, all I did was take a soldering iron
to the wax and remelt it.  Any remaining grit would sink to the bottom of
the channel (still there probably).  a little clean up by removing the small
amount of wax in the channels as Davey mentions. (I kept it at about 3/64ths
inch).  It took all of 10 minutes to do it for each successive grit size.
 The wax I used was that Gulf Wax for canning you can find it at the grocery
store.  I would probably go with a harder wax next time... like that of a
good quality candle.

I used match sticks for spacers between the tiles.  I think if I could have
found something a hair bigger I would have... not so much for the extra
width between tiles, but for extra tile exposure from the "surface" of the
concrete.

I do not recommend using aluminum foil to fill in extra spaces where partial
tiles could (but shouldn't) go.  It seems aluminum reacts chemically with
the lime in the concrete.  I think I would use balsa wood... easily yanked
out after curing.

In fact, using 3/32 or 1/8 square balsa wood would be a great replacement
for the match sticks I bet.

-Bill

On Tue, May 12, 2009 at 1:07 PM, <stainless_steel at suddenlink.net> wrote:

> Bob-
>
> Make the channels only (and keep them this way) two thirty seconds
> (2/32ndths) of an inch deep, by waxing the tool as per my article, and you
> will decide that what you wrote below can only be true for a tool that has
> no wax in the channels.
>
> You see, when I made my first channelled tile tool, I did not have any idea
> how to keep the grit from running away down through the deep channels- and
> yes, it ran out quickly when mirror was on top. That is the PRIMARY reason I
> came up with the waxing idea. I asure you that the grit will stay in place-
> I mean, as the grit becomes spent, only a little bit escapes from the tool,
> even if you are starting with coarse carborundum.
>
> After your tiles come to curve, wet the back of the mirror, and watch the
> very strange appearing action: with all the strokes there will be a grey,
> "amoeba" like creature, on each tile, surging back and forth in almost
> identical fashion- just keep the was between the tiles excavated down to
> about 2/32ths of an inch in depth- as you grind, the tiles will come down to
> the level of the wax, and you will have to take a break, and use a little
> screwdriver (very little) and scrape a tiny amount of the wax out between
> the tiles. You have the best of both worlds; the tile tool will behave as a
> monolithic tool in terms of grit economy, and any "rogue grit" will get
> trapped in the wax, if that accident happens.
>
> Try a tool with very shallow channels- you will turn your back on
> monolithic grinding tools-
>
> Be well, Bob, all-
>
> DLZ-130
>
> P.S.- With my first mirror, a Willman Bell kit, the eight inch blank and
> matching monolithic tool seized during fine grinding; also got my only huge
> gouge too. My second mirror was a 12.5" with an all ceramic tool, large
> Terra Cotta floor tiles nipped round and laminated, together, and put hexes
> on its face, and left them about the width of a kitchen matchstick apart.
> Immediaztely I started hogging out, the grit ran away into the abyss. I
> promply waxed those little linear spaces in between tiiles, and presto: NO
> MORE "DISAPPEARING GRIT" with the mirror on top. Works like a dream. One or
> two of the list members have tried this and it works unbelievably well.
>
> Some one came to Enid and bought the full thickness Corning 16" blank and
> two featured here (I think it was Ron Gafron)- and the others who've tried
> it and done the waxing as per the article, have not complained about losing
> grit. That's what the waxing of the channels is for, and it works well. Why
> did I not explain that in the article? Maybe I did. I think I will go back
> and read it again.
>
> http://www.atmsite.org/contrib/Harbour/Tool.html
>
>
>  Ken, I have looked through the glass and looked at the grit/glass
>> that gets washed off of the tool afterwords.  Everything that
>> starts out in a groove stays there.  Much of what is on the tiles
>> falls down after a roll or two.  Unused grit that gets recovered
>> from the wash water ends up being on the order of 90% or more
>> whereas a solid tool produces about 10% unused grit.  Not all
>> that good on using the grit when channeled tools are used.
>> The Newport "channeling" doesn't help with the vacuum problem all
>> that much as there is no point where the channel gets to the
>> outside of the tool.  Fill the channel with water and you get a
>> nice lock.  I occasionally do channel a tile tool but that is
>> just a scratch from the center to the edge of the tool, just for
>> an air passage rather than a deep channel for holding grit.
>> Bob May
>>
>
> rmay at nethere.com
> http: slash /nav.to slash bobmay
> http: slash /bobmay dot astronomy.net
>
> _______________________________________________
> ATM mailing list http://www.atmlist.net/
>

From gfbrandenburg at yahoo.com  Mon May 18 10:27:59 2009
From: gfbrandenburg at yahoo.com (Guy Brandenburg)
Date: Sun, 17 May 2009 18:27:59 -0700 (PDT)
Subject: [ATM] [Fwd: Re: Polyurethane tiles]
Message-ID: <976535.11213.qm@web111507.mail.gq1.yahoo.com>

Yes, I know someone who actually used marbles (aka aggies; that is to say, balls of glass that used to be used in children's games about 40+? years ago) in his tool. 
Hmm. I happen to have a whole lot of small blanks, roughly 1 to 2 inches in diameter, lots of different shapes, left over from the Korean War era. Maybe I should use them, cast in dental stone, for tools.
I made a cement tool, but it's incredibly heavy, and I kept being afraid of little particles of stuff from it coming off and messing up the glass.


Guy Brandenburg, Washington, DC
My home page on astronomy, mathematics, education:
http://home.earthlink.net/~gfbranden/GFB_Home_Page.html
or else 
http://tinyurl.com/r6fh2

=============================
"Education isn't rocket science. It's much, much harder."
(Author unknown)


--- On Sun, 5/17/09, Bill Wheaton <junkwheaton at gmail.com> wrote:

From: Bill Wheaton <junkwheaton at gmail.com>
Subject: Re: [ATM] [Fwd: Re: Polyurethane tiles]
To: "Bob May" <rmay at nethere.com>
Cc: atm at atmlist.net
Date: Sunday, May 17, 2009, 9:05 PM

I'm surprised Davey hasn't piped up, but he recommends concrete/tile tools.
 I tried it on his instruction and it worked fine with his method for my
12.5"? Check my blog for plenty of pictures, videos etc. as I document my
project. http://pythiashat.blogspot.com.? or my youtube page:
http://www.youtube.com/user/tabhorian
Also Francis O'Reilly has a several videos dedicated to making a lap with
dental stone starting here: http://www.youtube.com/watch?v=SZpov8cjDic
As Bob says, use the really hard floor tiles.? Mine were in a 12"x12" sheet
I found at a big box store.? (soak in water to get rid of the paper
backing... see the pics.)

I really recommend making videos and sharing them.? It's not hard at all,
and we can all benefit.? To not do them leaves our hobby in the dark ages.
 You can find out how do anything from knitting to rocketry to fun with
thermite and propane tanks to mag lev to aluminum casting and telescope
making.

-Bill Wheaton

On Tue, May 12, 2009 at 4:56 PM, Bob May <rmay at nethere.com> wrote:

> Please understand that there are two types of tiles sold for
> houses, etc.
> There is the wall tile.? This is a soft tile with a coating on
> the one surface so that it looks pretty.? Not good for making
> tile tools as they are as soft as, if not softer than, the stone
> used to hold them.
> There is also the floor tile.? These are intended to be walked on
> and thus are a lot harder than the wall tiles.? These are usually
> done in smaller sizes and are of a single color and need to have
> wax applied to get a polished surface.? They also tend to look
> like they were cast in a closed mold rather than the wall tile
> that looks like it got painted on a half mold.
> I'll note that you can also use glass cut up for tiles as well as
> hard stones to do the job.? I'm mostly using glass for tools now
> as the glass is readily available.
> Bob May
>
> rmay at nethere.com
> http: slash /nav.to slash bobmay
> http: slash /bobmay dot astronomy.net
>
>
> _______________________________________________
> ATM mailing list http://www.atmlist.net/
>
_______________________________________________
ATM mailing list http://www.atmlist.net/



      

From gfbrandenburg at yahoo.com  Mon May 18 10:39:45 2009
From: gfbrandenburg at yahoo.com (Guy Brandenburg)
Date: Sun, 17 May 2009 18:39:45 -0700 (PDT)
Subject: [ATM] making tile tools (was  Re: Polyurethane tiles)
Message-ID: <489549.80462.qm@web111514.mail.gq1.yahoo.com>

I found that if you use dental stone, then you don't have to worry about the channels at all. The stone is way softer than the hex tiles, so it wears down the same as the tiles. Wash it off well when changing grits; a toothbrush is a good idea. Perhaps for the first few minutes on the new, smaller grit there might be the odd grain of the old grit that comes up. But keep it up for 45 minutes to an hour, and there is no way that any of the old grit is going to remain.
I've tried the method with channels and wax, and it's a royal PITA.? Especially since it involves using epoxy and so on.
Just lay the hex tiles or whatever you are using directly on the mirror. Or almost on the mirror - you need a layer or two of saran wrap or some such thing. Make you dam - and make it REALLY strong!!! Cardboard won't work! Then mix up your batter - sorry, you dental plaster, with the proper amounts calculated correctly, agitate just a bit to release any bubbles, and then wait for a couple of hours until it's all set up and hardened. Then you are good to go.
One other thing: if y ou let your dental-stone and all get dry for a few days, then you will need to soak it in water for a while before using it. Found that out the hard way.

Guy Brandenburg, Washington, DC
My home page on astronomy, mathematics, education:
http://home.earthlink.net/~gfbranden/GFB_Home_Page.html
or else 
http://tinyurl.com/r6fh2

=============================
"Education isn't rocket science. It's much, much harder."
(Author unknown)


--- On Sun, 5/17/09, Bill Wheaton <junkwheaton at gmail.com> wrote:

From: Bill Wheaton <junkwheaton at gmail.com>
Subject: Re: [ATM] ATM:ATM: reply, forward Re: Polyurethane tiles
To: stainless_steel at suddenlink.net
Cc: "ATM list" <atm at atmlist.net>
Date: Sunday, May 17, 2009, 9:23 PM

I gotta second Davey's method.? Hard to find the hex tiles anymore so I used
square ones.
One thing I will say... between grits, all I did was take a soldering iron
to the wax and remelt it.? Any remaining grit would sink to the bottom of
the channel (still there probably).? a little clean up by removing the small
amount of wax in the channels as Davey mentions. (I kept it at about 3/64ths
inch).? It took all of 10 minutes to do it for each successive grit size.
 The wax I used was that Gulf Wax for canning you can find it at the grocery
store.? I would probably go with a harder wax next time... like that of a
good quality candle.

I used match sticks for spacers between the tiles.? I think if I could have
found something a hair bigger I would have... not so much for the extra
width between tiles, but for extra tile exposure from the "surface" of the
concrete.

I do not recommend using aluminum foil to fill in extra spaces where partial
tiles could (but shouldn't) go.? It seems aluminum reacts chemically with
the lime in the concrete.? I think I would use balsa wood... easily yanked
out after curing.

In fact, using 3/32 or 1/8 square balsa wood would be a great replacement
for the match sticks I bet.

-Bill

On Tue, May 12, 2009 at 1:07 PM, <stainless_steel at suddenlink.net> wrote:

> Bob-
>
> Make the channels only (and keep them this way) two thirty seconds
> (2/32ndths) of an inch deep, by waxing the tool as per my article, and you
> will decide that what you wrote below can only be true for a tool that has
> no wax in the channels.
>
> You see, when I made my first channelled tile tool, I did not have any idea
> how to keep the grit from running away down through the deep channels- and
> yes, it ran out quickly when mirror was on top. That is the PRIMARY reason I
> came up with the waxing idea. I asure you that the grit will stay in place-
> I mean, as the grit becomes spent, only a little bit escapes from the tool,
> even if you are starting with coarse carborundum.
>
> After your tiles come to curve, wet the back of the mirror, and watch the
> very strange appearing action: with all the strokes there will be a grey,
> "amoeba" like creature, on each tile, surging back and forth in almost
> identical fashion- just keep the was between the tiles excavated down to
> about 2/32ths of an inch in depth- as you grind, the tiles will come down to
> the level of the wax, and you will have to take a break, and use a little
> screwdriver (very little) and scrape a tiny amount of the wax out between
> the tiles. You have the best of both worlds; the tile tool will behave as a
> monolithic tool in terms of grit economy, and any "rogue grit" will get
> trapped in the wax, if that accident happens.
>
> Try a tool with very shallow channels- you will turn your back on
> monolithic grinding tools-
>
> Be well, Bob, all-
>
> DLZ-130
>
> P.S.- With my first mirror, a Willman Bell kit, the eight inch blank and
> matching monolithic tool seized during fine grinding; also got my only huge
> gouge too. My second mirror was a 12.5" with an all ceramic tool, large
> Terra Cotta floor tiles nipped round and laminated, together, and put hexes
> on its face, and left them about the width of a kitchen matchstick apart.
> Immediaztely I started hogging out, the grit ran away into the abyss. I
> promply waxed those little linear spaces in between tiiles, and presto: NO
> MORE "DISAPPEARING GRIT" with the mirror on top. Works like a dream. One or
> two of the list members have tried this and it works unbelievably well.
>
> Some one came to Enid and bought the full thickness Corning 16" blank and
> two featured here (I think it was Ron Gafron)- and the others who've tried
> it and done the waxing as per the article, have not complained about losing
> grit. That's what the waxing of the channels is for, and it works well. Why
> did I not explain that in the article? Maybe I did. I think I will go back
> and read it again.
>
> http://www.atmsite.org/contrib/Harbour/Tool.html
>
>
>? Ken, I have looked through the glass and looked at the grit/glass
>> that gets washed off of the tool afterwords.? Everything that
>> starts out in a groove stays there.? Much of what is on the tiles
>> falls down after a roll or two.? Unused grit that gets recovered
>> from the wash water ends up being on the order of 90% or more
>> whereas a solid tool produces about 10% unused grit.? Not all
>> that good on using the grit when channeled tools are used.
>> The Newport "channeling" doesn't help with the vacuum problem all
>> that much as there is no point where the channel gets to the
>> outside of the tool.? Fill the channel with water and you get a
>> nice lock.? I occasionally do channel a tile tool but that is
>> just a scratch from the center to the edge of the tool, just for
>> an air passage rather than a deep channel for holding grit.
>> Bob May
>>
>
> rmay at nethere.com
> http: slash /nav.to slash bobmay
> http: slash /bobmay dot astronomy.net
>
> _______________________________________________
> ATM mailing list http://www.atmlist.net/
>
_______________________________________________
ATM mailing list http://www.atmlist.net/



      

From junkwheaton at gmail.com  Mon May 18 10:44:19 2009
From: junkwheaton at gmail.com (Bill Wheaton)
Date: Sun, 17 May 2009 21:44:19 -0400
Subject: [ATM] beveling edge during figuring stage
In-Reply-To: <8BA4A3BD9E574A32B374D200BB6958D1@D5GHLR11>
References: <469487.67570.qm@web81905.mail.mud.yahoo.com>
	<0A9AC10B576A46538358769F7E599CF7@R101>
	<8BA4A3BD9E574A32B374D200BB6958D1@D5GHLR11>
Message-ID: <cd0f54500905171844y35c26333vb6344b4b50b95ae0@mail.gmail.com>

I ended up rounding my bevel.  It made no sense to me to have a square edge,
and by the same token, not even the 135 degree edge you get with a 45 degree
bevel.
So with a 1.5" x 2.5" x 0.75" block of read oak with a piece of aluminum
flashing taped to it with double sided carpet tape I spent one evening going
down through the grit sizes until the edge was nearly as polished as the
face was, and it was rounded over, not bevelled.  And the aluminum/wood gave
the process a little more "give" than you get with a stone.
I'm naturally careful anyway, so I didn't get any new scratches because of
this.  It was a slow but rewarding effort, I think.

-Bill

On Thu, May 7, 2009 at 3:27 PM, Francis J. O'Reilly <foreilly at bestweb.net>wrote:

> I tend to agree with David, leave it alone.
>
> My concern would be greater if there was no bevel at all during polishing,
> I
> like to allow a little bevel room at the edge during polishing to avoid the
> potential of large chips.
>
> Francis J. O'Reilly
> ----- Original Message ----- From: <stainless_steel at suddenlink.net>
> To: <blaktony86 at yahoo.com>; <atm at atmlist.net>
> Sent: Thursday, May 07, 2009 8:26 AM
> Subject: Re: [ATM] beveling edge during figuring stage
>
>
>
>  Personally,
>>
>> I would leave it there, leave it alone. A beveled chip would not be any
>> prettier than an unbeveled chip. Just think of the rest of the mirror,
>> what a fine job it will do. After you get it coated, put a little dab of
>> black enamel paint on the little chip, if it bothers you. My two cents.
>>
>> DLZ-130
>>
>>
>> ----- Original Message ----- From: "TONY BLAKESLEY" <blaktony86 at yahoo.com
>> >
>> To: <atm at atmlist.net>
>> Sent: Wednesday, May 06, 2009 2:33 PM
>> Subject: [ATM] beveling edge during figuring stage
>>
>>
>> Hello,
>>
>> I am in my final stages of figuring but this annoying little chip/bubble
>> is catching on the pitch at the extreme edge of the mirror. As of now,
>> there is maybe a 1/32" bevel. This tiny chip is making my figuring strokes
>> less perfect and its showing up on the Ronchi Test. The ronchigram shows a
>> tiny little pit at the extreme edge on the bevel and some wierd marks. The
>> ronchi lines dont skew around it but you can just barely see a noticeable
>> surface distoration because of the chip.
>>
>> Would it be safe to bevel the edge this late in the game? I would rather
>> not go back to fine grinding as I am getting close to a nice figure. If I
>> increase the bevel to 1/16" or 1/8" the chip will be gone. Is it worth
>> risk scratching the mirror to bevel the mirror or should I leave it alone?
>>
>> Thanks,
>>
>> Tony
>> _______________________________________________
>> ATM mailing list http://www.atmlist.net/
>>
>>
>>
>> --------------------------------------------------------------------------------
>>
>>
>>
>> No virus found in this incoming message.
>> Checked by AVG - www.avg.com
>> Version: 8.5.325 / Virus Database: 270.12.21/2102 - Release Date: 05/07/09
>> 05:57:00
>>
>> _______________________________________________
>> ATM mailing list http://www.atmlist.net/
>>
>
> _______________________________________________
> ATM mailing list http://www.atmlist.net/
>

From mbartels at bbastrodesigns.com  Mon May 18 11:16:23 2009
From: mbartels at bbastrodesigns.com (Mel Bartels)
Date: Sun, 17 May 2009 19:16:23 -0700
Subject: [ATM] [Fwd: Re: Polyurethane tiles]
In-Reply-To: <976535.11213.qm@web111507.mail.gq1.yahoo.com>
References: <976535.11213.qm@web111507.mail.gq1.yahoo.com>
Message-ID: <002301c9d75e$a89ed910$f9dc8b30$@com>

>>>
I made a cement tool, but it's incredibly heavy, and I kept being afraid of
little particles of stuff from it coming off and messing up the glass.
<<<

I used concrete tools for a number of years.  Their heaviness contributed to
their cracking because I'd lay them down too hard or nick them somehow.  I
didn't have problems with particles causing scratches.

Mel Bartels


From baldjeff at comcast.net  Mon May 18 12:09:52 2009
From: baldjeff at comcast.net (Jeff Baldwin)
Date: Sun, 17 May 2009 20:09:52 -0700
Subject: [ATM] [Fwd: Re: Polyurethane tiles]
References: <976535.11213.qm@web111507.mail.gq1.yahoo.com>
	<002301c9d75e$a89ed910$f9dc8b30$@com>
Message-ID: <EC0FB7D663B949B5A73B94BA6696061F@glendaspc>

Cement has roughly the same density as glass, so it would be no heavier than 
a similarily sized glass tool. Also, since pressure is the prime ingredient 
in polishing, I like heavy concrete tools.
Bald

Jeff and Glenda Baldwin
Lathrop, CA
www.agetawaylogcabin.com
www.stocktonastro.org



>>>>
> I made a cement tool, but it's incredibly heavy, and I kept being afraid 
> of
> little particles of stuff from it coming off and messing up the glass.
> <<<
>
> I used concrete tools for a number of years.  Their heaviness contributed 
> to
> their cracking because I'd lay them down too hard or nick them somehow.  I
> didn't have problems with particles causing scratches.
>
> Mel Bartels
>
> _______________________________________________
> 


From gilboastro at yahoo.com  Mon May 18 12:10:10 2009
From: gilboastro at yahoo.com (Gil McFarlane)
Date: Sun, 17 May 2009 20:10:10 -0700 (PDT)
Subject: [ATM] Anyone going to RTMC?
Message-ID: <253349.97241.qm@web62105.mail.re1.yahoo.com>


I'm going, but sadly, I don't think my mount will be ready in time.  

Ross (Sackett) are you going this year?   Have a new scope?


- Gil






      

From atmer at flash.net  Mon May 18 12:36:10 2009
From: atmer at flash.net (Anthony Stillman)
Date: Sun, 17 May 2009 20:36:10 -0700 (PDT)
Subject: [ATM] Anyone going to RTMC?
In-Reply-To: <253349.97241.qm@web62105.mail.re1.yahoo.com>
Message-ID: <628963.59781.qm@web82004.mail.mud.yahoo.com>


I'm not going.  Didn't send in my box tops.  Even so, OUT BACK still rules.  Take that you out front and insiders.

If anyone gets something great (in your opinion) at the swap meet, please post to the list.  At least I can live vicariously. 

Anthony




From mbartels at bbastrodesigns.com  Mon May 18 12:43:22 2009
From: mbartels at bbastrodesigns.com (Mel Bartels)
Date: Sun, 17 May 2009 20:43:22 -0700
Subject: [ATM] [Fwd: Re: Polyurethane tiles]
In-Reply-To: <EC0FB7D663B949B5A73B94BA6696061F@glendaspc>
References: <976535.11213.qm@web111507.mail.gq1.yahoo.com>
	<002301c9d75e$a89ed910$f9dc8b30$@com>
	<EC0FB7D663B949B5A73B94BA6696061F@glendaspc>
Message-ID: <003001c9d76a$d1ca2180$755e6480$@com>

>>>
Cement has roughly the same density as glass, so it would be no heavier than

a similarily sized glass tool. Also, since pressure is the prime ingredient 
in polishing, I like heavy concrete tools.
<<<


Well, I'm not convinced that density has anything to do with it.  The tool
has to be rigid.  To satisfy that, I made my concrete several inches thick;
way heavier than an equivalent glass or plaster tool.

Mel Bartels



From rmay at nethere.com  Mon May 18 14:04:29 2009
From: rmay at nethere.com (Bob May)
Date: Sun, 17 May 2009 22:04:29 -0700
Subject: [ATM] making tile tools (was  Re: Polyurethane tiles)
References: <489549.80462.qm@web111514.mail.gq1.yahoo.com>
Message-ID: <001a01c9d776$20888360$8f78fea9@amd>

Guy, isn't it amazing how fast the dental stone soaks up the
water when in the fine grits?  I usually leave a tool in the
water for about 5 minutes before starting a session - please
remember that the class is only done once a week so things have a
good time to dry out.
I'm now using Hyrdostone and thicker glass pieces for making a
tool.  Cheaper and the glass supply is easy to get.  Enclosed on
the private email are some photos of the ultralightweight mirror
blank from David Davis.  Yes, that blank really is floating in
the water pan!  Unfortunately, the list deletes such attachments.
Bob May

rmay at nethere.com
http: slash /nav.to slash bobmay
http: slash /bobmay dot astronomy.net


From rmay at nethere.com  Mon May 18 14:06:25 2009
From: rmay at nethere.com (Bob May)
Date: Sun, 17 May 2009 22:06:25 -0700
Subject: [ATM] Anyone going to RTMC?
References: <253349.97241.qm@web62105.mail.re1.yahoo.com>
Message-ID: <001f01c9d776$6600a1c0$8f78fea9@amd>

I'll probably see you up there on Sat.  Be carrying the
ultralightweight mirror around in a box.
Bob May

rmay at nethere.com
http: slash /nav.to slash bobmay
http: slash /bobmay dot astronomy.net



From tstokes at pacbell.net  Mon May 18 15:18:47 2009
From: tstokes at pacbell.net (Tom Stokes)
Date: Sun, 17 May 2009 23:18:47 -0700
Subject: [ATM] making tile tools (was  Re: Polyurethane tiles)
References: <489549.80462.qm@web111514.mail.gq1.yahoo.com>
	<001a01c9d776$20888360$8f78fea9@amd>
Message-ID: <D4B23D40109345788647E3D061EF00EB@tom>

> the private email are some photos of the ultralightweight mirror
> blank from David Davis.  Yes, that blank really is floating in
> the water pan!  Unfortunately, the list deletes such attachments.

Hey Bob, send me the pictures and I'll put 'em up on my site.

Tom Stokes

----- Original Message ----- 
From: "Bob May" <rmay at nethere.com>
To: "Guy Brandenburg" <gfbrandenburg at yahoo.com>; <atm at atmlist.net>
Sent: Sunday, May 17, 2009 10:04 PM
Subject: Re: [ATM] making tile tools (was Re: Polyurethane tiles)


> Guy, isn't it amazing how fast the dental stone soaks up the
> water when in the fine grits?  I usually leave a tool in the
> water for about 5 minutes before starting a session - please
> remember that the class is only done once a week so things have a
> good time to dry out.
> I'm now using Hyrdostone and thicker glass pieces for making a
> tool.  Cheaper and the glass supply is easy to get.  Enclosed on
> the private email are some photos of the ultralightweight mirror
> blank from David Davis.  Yes, that blank really is floating in
> the water pan!  Unfortunately, the list deletes such attachments.
> Bob May
> 
> rmay at nethere.com
> http: slash /nav.to slash bobmay
> http: slash /bobmay dot astronomy.net
> 
> _______________________________________________
> ATM mailing list http://www.atmlist.net/


From don.surles at verizon.net  Mon May 18 19:34:33 2009
From: don.surles at verizon.net (don surles)
Date: Mon, 18 May 2009 06:34:33 -0400
Subject: [ATM] making tile tools (was  Re: Polyurethane tiles)
In-Reply-To: <001a01c9d776$20888360$8f78fea9@amd>
References: <489549.80462.qm@web111514.mail.gq1.yahoo.com>
	<001a01c9d776$20888360$8f78fea9@amd>
Message-ID: <300c6fde544e805cbed7022296185300@verizon.net>

it is amazing to me that amateur mirror makers devote so much time to 
making a tool of something other than glass.

in the grand scheme of mirror making the cost of tool material is 
insignificant; having a dependable tool from beginning to end is 
critical to a successful ending.

why not just spring for a few dollars up front for a full size glass 
tool and avoid all the problems of casting, curing, scrubbing, tile 
glue-ing and replacement, etc associated with non-glass tools?

oh, grooved vs smooth tools?  i would choose a smooth tool over a 
grooved or channeled tool simply for the sake of being sure there is no 
contamination when changing grits size.  i have used both and find:

	1) there isn't a significant time difference in grinding with grooved 
vs smooth tool
	2) that during the pad polishing phase the grooves cause pads to 
unstick much faster than a non-grooved tool - and mixing new pads with 
old ones will cause surface ruffness that must be removed with the 
pitch lap.

my two cents on this topic.

Don...


On May 18, 2009, at 1:04 AM, Bob May wrote:

> Guy, isn't it amazing how fast the dental stone soaks up the
> water when in the fine grits?  I usually leave a tool in the
> water for about 5 minutes before starting a session - please
> remember that the class is only done once a week so things have a
> good time to dry out.
> I'm now using Hyrdostone and thicker glass pieces for making a
> tool.  Cheaper and the glass supply is easy to get.  Enclosed on
> the private email are some photos of the ultralightweight mirror
> blank from David Davis.  Yes, that blank really is floating in
> the water pan!  Unfortunately, the list deletes such attachments.
> Bob May
>
> rmay at nethere.com
> http: slash /nav.to slash bobmay
> http: slash /bobmay dot astronomy.net
>
> _______________________________________________
> ATM mailing list http://www.atmlist.net/
>
>
Don Surles


From rsackett00 at yahoo.com  Mon May 18 20:58:07 2009
From: rsackett00 at yahoo.com (Ross Sackett)
Date: Mon, 18 May 2009 04:58:07 -0700 (PDT)
Subject: [ATM] Anyone going to RTMC?
Message-ID: <117413.8807.qm@web59208.mail.re1.yahoo.com>


Hi Gil,

Yes, I will be there!  I am bringing my Captain Nemo scope so my folks can see it.

Ross
stardazed.com



--- On Sun, 5/17/09, Gil McFarlane <gilboastro at yahoo.com> wrote:

> From: Gil McFarlane <gilboastro at yahoo.com>
> Subject: [ATM] Anyone going to RTMC?
> To: "ATM" <atm at atmlist.net>
> Date: Sunday, May 17, 2009, 10:10 PM
> 
> I'm going, but sadly, I don't think my mount will be ready
> in time.? 
> 
> Ross (Sackett) are you going this
> year????Have a new scope?
> 
> 
> - Gil
> 
> 
> 
> 
> 
> 
> ? ? ? 
> _______________________________________________
> ATM mailing list http://www.atmlist.net/
> 

From pbunn at patbunn.com  Mon May 18 21:40:25 2009
From: pbunn at patbunn.com (Pat Bunn)
Date: Mon, 18 May 2009 08:40:25 -0400
Subject: [ATM] silvering in the 9/11 epoch
References: <Pine.LNX.4.44.0905160800210.20228-100000@uno.canit.se>
	<524985.48611.qm@web82008.mail.mud.yahoo.com>
Message-ID: <019b01c9d7b5$d240bc00$d201a8c0@pat1>

When you disolve pure silver in nitric acid be very careful of the fumes. 
One of the products is nitrogen dioxide which is extremely toxic and deadly 
in small amounts.

It has a somewhat delayed reaction from what I am told and if symtoms 
develop, death often occurs.

I have dome this reaction several times in preparing silver chloride - 
reacting the silver nitrate from the nitric acide with table salt. Be 
careful. I probably would not do this again after reading about the dangers 
closely. I'd buy the silver nitrate from a photo chemical supplier.

Pat Bunn





----- Original Message ----- 
From: "Anthony Stillman" <atmer at flash.net>
To: <atm at atmlist.net>
Sent: Saturday, May 16, 2009 3:34 AM
Subject: Re: [ATM] silvering in the 9/11 epoch


>
> Silver nitrate.
>
> As I recall one need only dissolve pure silver in hot nitric acid and let 
> the solution dry.  Not for sure certain I checked my 112 year old book of 
> recipes.  While it presents in detail how to slaughter a hen and how to 
> make nitro-glycerin as well as various fulminates, silver nitrate, being 
> readily available, didn't warrant discussion.  For that I had to surf the 
> net.  Let the solution dry in the dark.
>
> Its bad enough that chemicals that could be store bought 30 years ago now 
> require a background check and a sample of skin, but that a majority of 
> Americans actually believe that these hindrances make them safer, that's 
> down right scary.
>
> Anthony
>
>
>
>
> ----- Original Message ----
> From: Dominic-Luc Webb <dlwebb at canit.se>
> To: ATM Superheros <atm at atmlist.net>
> Sent: Friday, May 15, 2009 11:34:46 PM
> Subject: [ATM] silvering in the 9/11 epoch
>
>
> Specifically, Peacock Laboratories, Inc., which must have
> a lot of experience with silvering products, offers/recommends
> the following components, effectively a "kit":
>
> #93 Sensitizer 1 4 Oz. Bottle 16.20
> HE-400 S Silver Solution 1 4 Oz. Bottle 68.00
> HE-400 RReducer Solution 1 4 Oz. Bottle 67.00
> Spec. pkg. req. by Federal Law 20.00
> Shipping and Insurance Charges 198.30
>
> Total: $369.50
>
> Charges when reaching Sweden, multiply by 1.25 = $461.88 (3695 SEK)
>
> I have yet to determine if Swedish customs will allow a
> private person to take possession of these chemicals. Such
> problems with other chemicals has been an issue in the past.
>
> Do-able for most people with a job, but it is quite interesting
> how money burns in this post 9/11 world. As far as I know, the
> only special ingredient that is not easy/cheap to find is the
> silver nitrate. Shipping and insurance and then taxes on that is
> by far the biggest cost. Therefore, buying these things from a
> local source and doing the work there is far more cost effective
> than trying to ship it overseas. In fact, price to end up with
> this in Sweden is pretty close to what I paid for my round
> trip plane ticket to the States.
>
> I will arrive in Berkeley, CA Monday. I will see what can be
> done while I am there.
>
> Dominic
>
> _______________________________________________
> ATM mailing list http://www.atmlist.net/
>
> _______________________________________________
> ATM mailing list http://www.atmlist.net/ 


From gilboastro at yahoo.com  Mon May 18 23:27:49 2009
From: gilboastro at yahoo.com (Gil McFarlane)
Date: Mon, 18 May 2009 07:27:49 -0700 (PDT)
Subject: [ATM] Anyone going to RTMC?
Message-ID: <949451.92184.qm@web62105.mail.re1.yahoo.com>


sounds intriguing!   Can't wait to see what it looks like!
- Gil



--- On Sun, 5/17/09, Bob May <rmay at nethere.com> wrote:

> From: Bob May <rmay at nethere.com>
> Subject: Re: [ATM] Anyone going to RTMC?
> To: atm at atmlist.net
> Date: Sunday, May 17, 2009, 10:06 PM
> I'll probably see you up there on
> Sat.? Be carrying the
> ultralightweight mirror around in a box.
> Bob May
> 
> rmay at nethere.com
> http: slash /nav.to slash bobmay
> http: slash /bobmay dot astronomy.net
> 
> 
> _______________________________________________
> ATM mailing list http://www.atmlist.net/
> 


      

From ericandroberta at sbcglobal.net  Mon May 18 23:28:39 2009
From: ericandroberta at sbcglobal.net (D ERIC ALLEN)
Date: Mon, 18 May 2009 07:28:39 -0700 (PDT)
Subject: [ATM] ATM: Re: Protective coatings for silver films
Message-ID: <255015.90543.qm@web80506.mail.mud.yahoo.com>

The silver overcoat description can be found in ATM 1, p. 15.? "...a lacquer diluted six times with amyl acetate, is poured over the mirror and allowed to dry with the glass on its edge...luster of the silver will be prolonged for years, without...impairing its optical properties."? I seem to remember someone suggesting spin-drying the lacquer on a turntable, but it wasn't part of this description.
Somewhere between here and the list, my last letter got filled with a scattering of question marks.? We'll see what happens to this one.? As I send it, it doesn't contain a single question mark.
Eric Allen

From rozer at pacbell.net  Mon May 18 11:29:08 2009
From: rozer at pacbell.net (Richard Ozer)
Date: Sun, 17 May 2009 19:29:08 -0700
Subject: [ATM] Anyone going to RTMC?
In-Reply-To: <253349.97241.qm@web62105.mail.re1.yahoo.com>
References: <253349.97241.qm@web62105.mail.re1.yahoo.com>
Message-ID: <4A10C7F4.3070904@pacbell.net>

I currently plan on being there... arriving Friday AM.  Hope to see some 
of you there...

Gil McFarlane wrote:
> I'm going, but sadly, I don't think my mount will be ready in time.  
>
> Ross (Sackett) are you going this year?   Have a new scope?
>
>
> - Gil
>
>
>
>
>
>
>       
> _______________________________________________
> ATM mailing list http://www.atmlist.net/
>
>   

From gilboastro at yahoo.com  Mon May 18 23:31:01 2009
From: gilboastro at yahoo.com (Gil McFarlane)
Date: Mon, 18 May 2009 07:31:01 -0700 (PDT)
Subject: [ATM] Anyone going to RTMC?
Message-ID: <749095.11671.qm@web62108.mail.re1.yahoo.com>


Captain Nemo, ultralightweight mirror in a box.  My mind is reeling!

Perhaps there is a time Sat afternoon when folks on the list could meet at Ross's scope to chat?

(Ross will you be on the meadow again?)

- Gil

--- On Mon, 5/18/09, Ross Sackett <rsackett00 at yahoo.com> wrote:

> From: Ross Sackett <rsackett00 at yahoo.com>
> Subject: Re: [ATM] Anyone going to RTMC?
> To: atm at atmlist.net
> Date: Monday, May 18, 2009, 4:58 AM
> 
> Hi Gil,
> 
> Yes, I will be there!? I am bringing my Captain Nemo
> scope so my folks can see it.
> 
> Ross
> stardazed.com
> 
> 
> 
> --- On Sun, 5/17/09, Gil McFarlane <gilboastro at yahoo.com>
> wrote:
> 
> > From: Gil McFarlane <gilboastro at yahoo.com>
> > Subject: [ATM] Anyone going to RTMC?
> > To: "ATM" <atm at atmlist.net>
> > Date: Sunday, May 17, 2009, 10:10 PM
> > 
> > I'm going, but sadly, I don't think my mount will be
> ready
> > in time.? 
> > 
> > Ross (Sackett) are you going this
> > year????Have a new scope?
> > 
> > 
> > - Gil
> > 
> > 
> > 
> > 
> > 
> > 
> > ? ? ? 
> > _______________________________________________
> > ATM mailing list http://www.atmlist.net/
> > 
> _______________________________________________
> ATM mailing list http://www.atmlist.net/
> 


      

From Gregg.Swanson at microsoft.com  Mon May 18 23:50:10 2009
From: Gregg.Swanson at microsoft.com (Gregg Swanson)
Date: Mon, 18 May 2009 07:50:10 -0700
Subject: [ATM] Anyone going to RTMC?
In-Reply-To: <001f01c9d776$6600a1c0$8f78fea9@amd>
References: <253349.97241.qm@web62105.mail.re1.yahoo.com>
	<001f01c9d776$6600a1c0$8f78fea9@amd>
Message-ID: <D46DD847F1D118479ABF4CBB34B875B2125495D8D1@NA-EXMSG-C113.redmond.corp.microsoft.com>

How ultra-light? Or is this a teaser!  :)

Thanks,
Gregg

-----Original Message-----
From: atm-bounces at atmlist.net [mailto:atm-bounces at atmlist.net] On Behalf Of Bob May
Sent: Monday, May 18, 2009 12:06 AM
To: atm at atmlist.net
Subject: Re: [ATM] Anyone going to RTMC?

I'll probably see you up there on Sat.  Be carrying the
ultralightweight mirror around in a box.
Bob May

rmay at nethere.com
http: slash /nav.to slash bobmay
http: slash /bobmay dot astronomy.net


_______________________________________________
ATM mailing list http://www.atmlist.net/


From rsackett00 at yahoo.com  Tue May 19 00:37:26 2009
From: rsackett00 at yahoo.com (Ross Sackett)
Date: Mon, 18 May 2009 08:37:26 -0700 (PDT)
Subject: [ATM] Anyone going to RTMC?
Message-ID: <717479.51615.qm@web59207.mail.re1.yahoo.com>


Saturday I think I will set up by the vendor's tents near the (usual place for) the Meade tent for the morning judging, then come down to the meadow in the afternoon.  We should definitely all meet up.  

Ross

--- On Mon, 5/18/09, Gil McFarlane <gilboastro at yahoo.com> wrote:

> From: Gil McFarlane <gilboastro at yahoo.com>
> Subject: Re: [ATM] Anyone going to RTMC?
> To: atm at atmlist.net, "Ross Sackett" <rsackett00 at yahoo.com>
> Date: Monday, May 18, 2009, 9:31 AM
> 
> Captain Nemo, ultralightweight mirror in a box.? My
> mind is reeling!
> 
> Perhaps there is a time Sat afternoon when folks on the
> list could meet at Ross's scope to chat?
> 
> (Ross will you be on the meadow again?)
> 
> - Gil
> 
> --- On Mon, 5/18/09, Ross Sackett <rsackett00 at yahoo.com>
> wrote:
> 
> > From: Ross Sackett <rsackett00 at yahoo.com>
> > Subject: Re: [ATM] Anyone going to RTMC?
> > To: atm at atmlist.net
> > Date: Monday, May 18, 2009, 4:58 AM
> > 
> > Hi Gil,
> > 
> > Yes, I will be there!? I am bringing my Captain Nemo
> > scope so my folks can see it.
> > 
> > Ross
> > stardazed.com
> > 
> > 
> > 
> > --- On Sun, 5/17/09, Gil McFarlane <gilboastro at yahoo.com>
> > wrote:
> > 
> > > From: Gil McFarlane <gilboastro at yahoo.com>
> > > Subject: [ATM] Anyone going to RTMC?
> > > To: "ATM" <atm at atmlist.net>
> > > Date: Sunday, May 17, 2009, 10:10 PM
> > > 
> > > I'm going, but sadly, I don't think my mount will
> be
> > ready
> > > in time.? 
> > > 
> > > Ross (Sackett) are you going this
> > > year????Have a new scope?
> > > 
> > > 
> > > - Gil
> > > 
> > > 
> > > 
> > > 
> > > 
> > > 
> > > ? ? ? 
> > > _______________________________________________
> > > ATM mailing list http://www.atmlist.net/
> > > 
> > _______________________________________________
> > ATM mailing list http://www.atmlist.net/
> > 
> 
> 
> 
> 

From mjc5 at psu.edu  Tue May 19 02:09:19 2009
From: mjc5 at psu.edu (Michael Coslo)
Date: Mon, 18 May 2009 13:09:19 -0400
Subject: [ATM] silvering reagents and airline baggage
In-Reply-To: <53764.87.255.50.71.1242372754.squirrel@webmail.xs4all.nl>
References: <53764.87.255.50.71.1242372754.squirrel@webmail.xs4all.nl>
Message-ID: <27CCB86E-1162-4C18-9C74-3FCF4D83D140@psu.edu>


On May 15, 2009, at 3:32 AM, Marinus van der Lugt wrote:

> With the proper storage (air tight and including a silver protector  
> or a
> C02 flooding?), it seems to me that a silver coating would last much
> longer than a year.

The important part of protecting a silver mirror is keeping it from  
sulfur. This means keeping eggs away, and avoiding coal. If you have a  
coal furnace, don't silver in the winter. this means the local  
environment is an issue too.

I never thought of charging a container with inert gas. Might be good.

My mirror had not failed at the end of the year, but it was beginning  
to show some signs that I might want to replace it. The main problem  
was a few flecks here and there came off the mirror. You could see it  
by transmitted light. Could possibly be a delayed cleanliness issue,  
but a year isn't too bad.

Cleanliness is the number one most critical issue. My guideline ended  
up as being willing to bet my life that the mirror surface was clean  
enough, then clean it a few more times.

I tried to avoid using the Nitric at first, and used an alcohol  
cleaning, then acetone. It just wasn't good enough, the coating would  
go on in a patchy manner. Other considerations are:

The reactions are quick. I found that by storing the solutions in the  
refrigerator (or maybe an ice chest if you are nervous about having  
that stuff around food) was a big help.

Make sure that the dam you place around the mirror is strong enough. I  
lost a batch once when the dam failed.

You might want to look at neutralizing the nasty stuff after use. Keep  
in mind that there will be an exothermic reaction, so proceed slowly.

That film is unbelievably fragile until it dries. Rinse and let dry,  
don't touch it.

When you see your first successful slivered mirror, it's like freakin'  
magic!


My lawyers tell me I gotta do this:

This process uses stuff that might be dangerous, so don't ever, ever  
do this sort of thing, much better to sit in a nice safe chair and let  
entropy catch up to you.......

Seriously - silvering a mirror is nasty nasty nasty. Don't do it.  
You've been warned!



-73 de Mike N3LI -



From stainless_steel at suddenlink.net  Tue May 19 04:46:49 2009
From: stainless_steel at suddenlink.net (stainless_steel at suddenlink.net)
Date: Mon, 18 May 2009 14:46:49 -0500
Subject: [ATM] [Fwd: Re: Polyurethane tiles]
In-Reply-To: <cd0f54500905171805r4852a038odd5fab85174b8420@mail.gmail.com>
References: <Pine.LNX.4.44.0905110954040.28033-100000@uno.canit.se><C89B6E6A-F156-445A-8042-DB026D617009@psu.edu><004f01c9d344$3848c5e0$8f78fea9@amd>
	<cd0f54500905171805r4852a038odd5fab85174b8420@mail.gmail.com>
Message-ID: <55E85DC2F413447D97DC57B0583E5514@R101>

Thanks, Bill.

I have. But as I grow older, I grow more invisible. I almost can't see 
myself now.

By the way, listen up now, all of you'uns (who expect Okies to talk that 
way)- if I should disappear from the web, do not worry about my untimely 
deceasement. Rather, conclude that it was sabatoge to my www gear. At this 
moment, that is at an all time high. More, later (if threat passes).

BTW-does anyone know the status of "Flying Wing Man", aka, "Richard 
Schwartz?" I sent him an email after they let me out of the psych ward, but 
he did not answer it; that was two months ago. If anyone can help regarding 
his status (still above ground?) and why he would not answer an email to him 
from me, you might let me in on the secret-

DLZ-130


----- Original Message ----- 
From: "Bill Wheaton" <junkwheaton at gmail.com>
To: "Bob May" <rmay at nethere.com>
Cc: <atm at atmlist.net>
Sent: Sunday, May 17, 2009 8:05 PM
Subject: Re: [ATM] [Fwd: Re: Polyurethane tiles]


> I'm surprised Davey hasn't piped up, but he recommends concrete/tile 
> tools.
> I tried it on his instruction and it worked fine with his method for my
> 12.5"  Check my blog for plenty of pictures, videos etc. as I document my
> project. http://pythiashat.blogspot.com.  or my youtube page:
> http://www.youtube.com/user/tabhorian
> Also Francis O'Reilly has a several videos dedicated to making a lap with
> dental stone starting here: http://www.youtube.com/watch?v=SZpov8cjDic
> As Bob says, use the really hard floor tiles.  Mine were in a 12"x12" 
> sheet
> I found at a big box store.  (soak in water to get rid of the paper
> backing... see the pics.)
>
> I really recommend making videos and sharing them.  It's not hard at all,
> and we can all benefit.  To not do them leaves our hobby in the dark ages.
> You can find out how do anything from knitting to rocketry to fun with
> thermite and propane tanks to mag lev to aluminum casting and telescope
> making.
>
> -Bill Wheaton
>
> On Tue, May 12, 2009 at 4:56 PM, Bob May <rmay at nethere.com> wrote:
>
>> Please understand that there are two types of tiles sold for
>> houses, etc.
>> There is the wall tile.  This is a soft tile with a coating on
>> the one surface so that it looks pretty.  Not good for making
>> tile tools as they are as soft as, if not softer than, the stone
>> used to hold them.
>> There is also the floor tile.  These are intended to be walked on
>> and thus are a lot harder than the wall tiles.  These are usually
>> done in smaller sizes and are of a single color and need to have
>> wax applied to get a polished surface.  They also tend to look
>> like they were cast in a closed mold rather than the wall tile
>> that looks like it got painted on a half mold.
>> I'll note that you can also use glass cut up for tiles as well as
>> hard stones to do the job.  I'm mostly using glass for tools now
>> as the glass is readily available.
>> Bob May
>>
>> rmay at nethere.com
>> http: slash /nav.to slash bobmay
>> http: slash /bobmay dot astronomy.net
>>
>>
>> _______________________________________________
>> ATM mailing list http://www.atmlist.net/
>>
> _______________________________________________
> ATM mailing list http://www.atmlist.net/


--------------------------------------------------------------------------------



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From stainless_steel at suddenlink.net  Tue May 19 04:59:42 2009
From: stainless_steel at suddenlink.net (stainless_steel at suddenlink.net)
Date: Mon, 18 May 2009 14:59:42 -0500
Subject: [ATM] ATM:ATM: reply, forward Re: Polyurethane tiles
In-Reply-To: <cd0f54500905171821v3e5e51d8ye933fd781301b12d@mail.gmail.com>
References: <E0048BC4F79D47FDA7B508F2C0F88464@R101>
	<cd0f54500905171821v3e5e51d8ye933fd781301b12d@mail.gmail.com>
Message-ID: <3E6CAF8D2C8947D7ABE15FA489F6F938@R101>


I can get them for anyone who wants them, right here, not more than a good 
baseball pitcher's range away from me. However, they are no longer an inch 
in diameter, just as a Big Mac is no longer... well, you get my drift. 
"Winburne" who made those classy, white, cushion edge one inch (and two 
inch) hexes, is out of business.

Consolation: these come in colors!!!!! (3/4" in diameter, or a little over, 
I think- cushion edge, too- they would come to curve more quickly than the 
one inch tiles. BTW, that is why no one ever used the two inch Winburne 
hexes; too long to get to curve, and after retiling, too long to get back to 
curve.

DLZ-130

P.S.- My memory may be faulty; I may have actually meant 3/64ths; I think I 
did. I use a Starrett "Aircraft Reading" rule to think in, and to measure 
with (years ago, my 24" Starrett rule was $65) and one side is 1",  1/2", 
1/4",  on down to 64ths; the other side is 1.0",  .1",  .01". That is the 
side that lends itself to computations. By the way, the Starrett rules are 
straight edged enough to make a perfect three contact phereometer. With a 
little tiny brass pillow shaped to the right sagitta. For in the middle of 
the mirror.


----- Original Message ----- 
From: Bill Wheaton
To: stainless_steel at suddenlink.net
Sent: Sunday, May 17, 2009 8:21 PM
Subject: Re: [ATM] ATM:ATM: reply, forward Re: Polyurethane tiles


I gotta second Davey's method.  Hard to find the hex tiles anymore so I used 
square ones.


One thing I will say... between grits, all I did was take a soldering iron 
to the wax and remelt it.  Any remaining grit would sink to the bottom of 
the channel (still there probably).  a little clean up by removing the small 
amount of wax in the channels as Davey mentions. (I kept it at about 3/64ths 
inch).  It took all of 10 minutes to do it for each successive grit size. 
The wax I used was that Gulf Wax for canning you can find it at the grocery 
store.  I would probably go with a harder wax next time... like that of a 
good quality candle.


I used match sticks for spacers between the tiles.  I think if I could have 
found something a hair bigger I would have... not so much for the extra 
width between tiles, but for extra tile exposure from the "surface" of the 
concrete.


I do not recommend using aluminum foil to fill in extra spaces where partial 
tiles could (but shouldn't) go.  It seems aluminum reacts chemically with 
the lime in the concrete.  I think I would use balsa wood... easily yanked 
out after curing.


In fact, using 3/32 or 1/8 square balsa wood would be a great replacement 
for the match sticks I bet.


-Bill





On Tue, May 12, 2009 at 1:07 PM, <stainless_steel at suddenlink.net> wrote:

Bob-

Make the channels only (and keep them this way) two thirty seconds 
(2/32ndths) of an inch deep, by waxing the tool as per my article, and you 
will decide that what you wrote below can only be true for a tool that has 
no wax in the channels.

You see, when I made my first channelled tile tool, I did not have any idea 
how to keep the grit from running away down through the deep channels- and 
yes, it ran out quickly when mirror was on top. That is the PRIMARY reason I 
came up with the waxing idea. I asure you that the grit will stay in place- 
I mean, as the grit becomes spent, only a little bit escapes from the tool, 
even if you are starting with coarse carborundum.

After your tiles come to curve, wet the back of the mirror, and watch the 
very strange appearing action: with all the strokes there will be a grey, 
"amoeba" like creature, on each tile, surging back and forth in almost 
identical fashion- just keep the was between the tiles excavated down to 
about 2/32ths of an inch in depth- as you grind, the tiles will come down to 
the level of the wax, and you will have to take a break, and use a little 
screwdriver (very little) and scrape a tiny amount of the wax out between 
the tiles. You have the best of both worlds; the tile tool will behave as a 
monolithic tool in terms of grit economy, and any "rogue grit" will get 
trapped in the wax, if that accident happens.

Try a tool with very shallow channels- you will turn your back on monolithic 
grinding tools-

Be well, Bob, all-

DLZ-130

P.S.- With my first mirror, a Willman Bell kit, the eight inch blank and 
matching monolithic tool seized during fine grinding; also got my only huge 
gouge too. My second mirror was a 12.5" with an all ceramic tool, large 
Terra Cotta floor tiles nipped round and laminated, together, and put hexes 
on its face, and left them about the width of a kitchen matchstick apart. 
Immediaztely I started hogging out, the grit ran away into the abyss. I 
promply waxed those little linear spaces in between tiiles, and presto: NO 
MORE "DISAPPEARING GRIT" with the mirror on top. Works like a dream. One or 
two of the list members have tried this and it works unbelievably well.

Some one came to Enid and bought the full thickness Corning 16" blank and 
two featured here (I think it was Ron Gafron)- and the others who've tried 
it and done the waxing as per the article, have not complained about losing 
grit. That's what the waxing of the channels is for, and it works well. Why 
did I not explain that in the article? Maybe I did. I think I will go back 
and read it again.

http://www.atmsite.org/contrib/Harbour/Tool.html



Ken, I have looked through the glass and looked at the grit/glass
that gets washed off of the tool afterwords.  Everything that
starts out in a groove stays there.  Much of what is on the tiles
falls down after a roll or two.  Unused grit that gets recovered
from the wash water ends up being on the order of 90% or more
whereas a solid tool produces about 10% unused grit.  Not all
that good on using the grit when channeled tools are used.
The Newport "channeling" doesn't help with the vacuum problem all
that much as there is no point where the channel gets to the
outside of the tool.  Fill the channel with water and you get a
nice lock.  I occasionally do channel a tile tool but that is
just a scratch from the center to the edge of the tool, just for
an air passage rather than a deep channel for holding grit.
Bob May


rmay at nethere.com
http: slash /nav.to slash bobmay
http: slash /bobmay dot astronomy.net

_______________________________________________
ATM mailing list http://www.atmlist.net/







No virus found in this incoming message.
Checked by AVG - www.avg.com
Version: 8.5.339 / Virus Database: 270.12.33/2120 - Release Date: 05/18/09 
06:28:00 


From stainless_steel at suddenlink.net  Tue May 19 05:11:26 2009
From: stainless_steel at suddenlink.net (stainless_steel at suddenlink.net)
Date: Mon, 18 May 2009 15:11:26 -0500
Subject: [ATM] making tile tools (was  Re: Polyurethane tiles)
In-Reply-To: <300c6fde544e805cbed7022296185300@verizon.net>
References: <489549.80462.qm@web111514.mail.gq1.yahoo.com><001a01c9d776$20888360$8f78fea9@amd>
	<300c6fde544e805cbed7022296185300@verizon.net>
Message-ID: <72C7E2AC048A4627B14EEFB5F596EF3F@R101>

Well, Don, Bob, all-

Some people have to let their wine "breathe" before they will drink it, and 
they have to sniff of it, etc.,etc. There are probably other wine rituals 
too. But I don't do alcohol since my last disaster with it.

However, for the record, for me: there is a WORLD of difference between the 
performance of a channeled grinding tool and one that is monolithic. I will 
never forget that tortured sound of that first "skreak" in my 8" Willman 
Bell mirror blank, in fine grinding (about a 120 grit sized scratch-about 
all the way across the surface). And then, the seiquzed disks. First and 
last mirror with a monolithic tool; went to channeled tools, never got 
another scratch, and did plenty of work TOT.

Different strokes for different folks, I guess. Let's grind more and argue 
less. Only, with two torn rotator cuffs (one very badly-cannot even lie on 
that side) my glass strokin' days are over.

DLZ-130


----- Original Message ----- 
From: "don surles" <don.surles at verizon.net>
To: "Bob May" <rmay at nethere.com>
Cc: <atm at atmlist.net>
Sent: Monday, May 18, 2009 5:34 AM
Subject: Re: [ATM] making tile tools (was Re: Polyurethane tiles)


> it is amazing to me that amateur mirror makers devote so much time to
> making a tool of something other than glass.
>
> in the grand scheme of mirror making the cost of tool material is
> insignificant; having a dependable tool from beginning to end is
> critical to a successful ending.
>
> why not just spring for a few dollars up front for a full size glass
> tool and avoid all the problems of casting, curing, scrubbing, tile
> glue-ing and replacement, etc associated with non-glass tools?
>
> oh, grooved vs smooth tools?  i would choose a smooth tool over a
> grooved or channeled tool simply for the sake of being sure there is no
> contamination when changing grits size.  i have used both and find:
>
> 1) there isn't a significant time difference in grinding with grooved
> vs smooth tool
> 2) that during the pad polishing phase the grooves cause pads to
> unstick much faster than a non-grooved tool - and mixing new pads with
> old ones will cause surface ruffness that must be removed with the
> pitch lap.
>
> my two cents on this topic.
>
> Don...
>
>
> On May 18, 2009, at 1:04 AM, Bob May wrote:
>
>> Guy, isn't it amazing how fast the dental stone soaks up the
>> water when in the fine grits?  I usually leave a tool in the
>> water for about 5 minutes before starting a session - please
>> remember that the class is only done once a week so things have a
>> good time to dry out.
>> I'm now using Hyrdostone and thicker glass pieces for making a
>> tool.  Cheaper and the glass supply is easy to get.  Enclosed on
>> the private email are some photos of the ultralightweight mirror
>> blank from David Davis.  Yes, that blank really is floating in
>> the water pan!  Unfortunately, the list deletes such attachments.
>> Bob May
>>
>> rmay at nethere.com
>> http: slash /nav.to slash bobmay
>> http: slash /bobmay dot astronomy.net
>>
>> _______________________________________________
>> ATM mailing list http://www.atmlist.net/
>>
>>
> Don Surles
>
> _______________________________________________
> ATM mailing list http://www.atmlist.net/


--------------------------------------------------------------------------------



No virus found in this incoming message.
Checked by AVG - www.avg.com
Version: 8.5.339 / Virus Database: 270.12.33/2120 - Release Date: 05/18/09 
06:28:00


From stainless_steel at suddenlink.net  Tue May 19 05:13:29 2009
From: stainless_steel at suddenlink.net (stainless_steel at suddenlink.net)
Date: Mon, 18 May 2009 15:13:29 -0500
Subject: [ATM] ATM: Re: Protective coatings for silver films
In-Reply-To: <255015.90543.qm@web80506.mail.mud.yahoo.com>
References: <255015.90543.qm@web80506.mail.mud.yahoo.com>
Message-ID: <7E2E32620A6F445C8D2490E0BE7D6F9D@R101>

Thanks, Eric-

That's the formula I was hoping someone would provide.

DLZ-130


----- Original Message ----- 
From: "D ERIC ALLEN" <ericandroberta at sbcglobal.net>
To: <atm at atmlist.net>
Sent: Monday, May 18, 2009 9:28 AM
Subject: [ATM] ATM: Re: Protective coatings for silver films


The silver overcoat description can be found in ATM 1, p. 15. "...a lacquer 
diluted six times with amyl acetate, is poured over the mirror and allowed 
to dry with the glass on its edge...luster of the silver will be prolonged 
for years, without...impairing its optical properties." I seem to remember 
someone suggesting spin-drying the lacquer on a turntable, but it wasn't 
part of this description.
Somewhere between here and the list, my last letter got filled with a 
scattering of question marks. We'll see what happens to this one. As I send 
it, it doesn't contain a single question mark.
Eric Allen
_______________________________________________
ATM mailing list http://www.atmlist.net/


--------------------------------------------------------------------------------



No virus found in this incoming message.
Checked by AVG - www.avg.com
Version: 8.5.339 / Virus Database: 270.12.33/2120 - Release Date: 05/18/09 
06:28:00


From rmay at nethere.com  Tue May 19 05:50:37 2009
From: rmay at nethere.com (Bob May)
Date: Mon, 18 May 2009 13:50:37 -0700
Subject: [ATM] making tile tools (was  Re: Polyurethane tiles)
References: <489549.80462.qm@web111514.mail.gq1.yahoo.com><001a01c9d776$20888360$8f78fea9@amd>
	<C3D1A0B41545446496F923A4507E4A0D@HELENYLCMWAV95>
Message-ID: <001801c9d7fa$4caef4e0$8f78fea9@amd>

Looks like a number of people have asked for the photos.  They're
on the way!
The amazing part is the blank is so light that it really floats
in water!
Bob May

rmay at nethere.com
http: slash /nav.to slash bobmay
http: slash /bobmay dot astronomy.net



From rmay at nethere.com  Tue May 19 05:56:25 2009
From: rmay at nethere.com (Bob May)
Date: Mon, 18 May 2009 13:56:25 -0700
Subject: [ATM] Anyone going to RTMC?
References: <253349.97241.qm@web62105.mail.re1.yahoo.com>
	<001f01c9d776$6600a1c0$8f78fea9@amd>
	<579846.47791.qm@web50011.mail.re2.yahoo.com>
Message-ID: <001e01c9d7fb$1c70fde0$8f78fea9@amd>

RTMC is held each year just outside of Big Bear Lake, CA. just
above Riverside in the little community of Williams at the Boy
Scout Camp.  There is a sign at the entrance to the community.
It is held on Memorial Day weekend from Fri. to Mon.  The group
that puts it on has a contract with the Boy Scouts for that
weekend and it doesn't matter the phase of the moon.
The altitude is 7200'
The meet is open to all and meals are served.  It will cost near
$100 for the weekend and $26 for a day- no meals.
Bob May

rmay at nethere.com
http: slash /nav.to slash bobmay
http: slash /bobmay dot astronomy.net



From rmay at nethere.com  Tue May 19 05:57:53 2009
From: rmay at nethere.com (Bob May)
Date: Mon, 18 May 2009 13:57:53 -0700
Subject: [ATM] Anyone going to RTMC?
References: <253349.97241.qm@web62105.mail.re1.yahoo.com><001f01c9d776$6600a1c0$8f78fea9@amd>
	<D46DD847F1D118479ABF4CBB34B875B2125495D8D1@NA-EXMSG-C113.redmond.corp.microsoft.com>
Message-ID: <002501c9d7fb$510c6620$8f78fea9@amd>

If you haven't been following the other thread, the blank floats
in water!  Maybe see you there.
Bob May

rmay at nethere.com
http: slash /nav.to slash bobmay
http: slash /bobmay dot astronomy.net



From tstokes at pacbell.net  Tue May 19 07:54:03 2009
From: tstokes at pacbell.net (Tom Stokes)
Date: Mon, 18 May 2009 15:54:03 -0700
Subject: [ATM] making tile tools (was  Re: Polyurethane tiles)
References: <489549.80462.qm@web111514.mail.gq1.yahoo.com><001a01c9d776$20888360$8f78fea9@amd><C3D1A0B41545446496F923A4507E4A0D@HELENYLCMWAV95>
	<001801c9d7fa$4caef4e0$8f78fea9@amd>
Message-ID: <38E5B2BB899C46FABCBD366487108295@tom>

Here they are.

http://www.mirrorgrindingmachine.com/transient/floatingmirror.jpg
http://www.mirrorgrindingmachine.com/transient/floatingmirror2.jpg
http://www.mirrorgrindingmachine.com/transient/mirror&tool.jpg
http://www.mirrorgrindingmachine.com/transient/mirrorside.jpg

----- Original Message ----- 
From: "Bob May" <rmay at nethere.com>
To: <atm at atmlist.net>
Sent: Monday, May 18, 2009 1:50 PM
Subject: Re: [ATM] making tile tools (was Re: Polyurethane tiles)


> Looks like a number of people have asked for the photos.  They're
> on the way!
> The amazing part is the blank is so light that it really floats
> in water!
> Bob May
> 
> rmay at nethere.com
> http: slash /nav.to slash bobmay
> http: slash /bobmay dot astronomy.net
> 
> 
> _______________________________________________
> ATM mailing list http://www.atmlist.net/

From wkitty42 at windstream.net  Tue May 19 07:58:18 2009
From: wkitty42 at windstream.net (waldo kitty)
Date: Mon, 18 May 2009 18:58:18 -0400
Subject: [ATM] making tile tools (was  Re: Polyurethane tiles)
In-Reply-To: <300c6fde544e805cbed7022296185300@verizon.net>
References: <489549.80462.qm@web111514.mail.gq1.yahoo.com>	<001a01c9d776$20888360$8f78fea9@amd>
	<300c6fde544e805cbed7022296185300@verizon.net>
Message-ID: <4A11E80A.6050707@windstream.net>

don surles wrote:
> it is amazing to me that amateur mirror makers devote so much time to 
> making a tool of something other than glass.
> 
> in the grand scheme of mirror making the cost of tool material is 
> insignificant; having a dependable tool from beginning to end is 
> critical to a successful ending.
> 
> why not just spring for a few dollars up front for a full size glass 
> tool and avoid all the problems of casting, curing, scrubbing, tile 
> glue-ing and replacement, etc associated with non-glass tools?

i'd rather use that tool as a blank for another mirror instead of as the start 
of a lens ;) :P

-- 
        _\/
       (@@)                      Waldo Kitty, Waldo's Place USA
__ooO_( )_Ooo_____________________ telnet://bbs.wpusa.dynip.com
_|_____|_____|_____|_____|_____|_____ http://www.wpusa.dynip.com
____|_____|_____|_____|_____|_____|____ ftp://ftp.wpusa.dynip.com
_|_Eat_SPAM_to_email_me!_YUM!__|_____ wkitty42 -at- windstream.net

From mbartels at bbastrodesigns.com  Tue May 19 10:11:14 2009
From: mbartels at bbastrodesigns.com (Mel Bartels)
Date: Mon, 18 May 2009 18:11:14 -0700
Subject: [ATM] silvering reagents and airline baggage
In-Reply-To: <27CCB86E-1162-4C18-9C74-3FCF4D83D140@psu.edu>
References: <53764.87.255.50.71.1242372754.squirrel@webmail.xs4all.nl>
	<27CCB86E-1162-4C18-9C74-3FCF4D83D140@psu.edu>
Message-ID: <002401c9d81e$b9464b20$2bd2e160$@com>

>>>
The important part of protecting a silver mirror is keeping it from  
sulfur. This means keeping eggs away, and avoiding coal. If you have a  
coal furnace, don't silver in the winter. this means the local  
environment is an issue too.
<<<


I remember John Hall from the UK using a cloth bag pressed against the
mirror face (filled with ?).  IIRC, his coatings lasted years.

Mel Bartels


From gilboastro at yahoo.com  Tue May 19 10:26:17 2009
From: gilboastro at yahoo.com (Gil McFarlane)
Date: Mon, 18 May 2009 18:26:17 -0700 (PDT)
Subject: [ATM] Anyone going to RTMC?
Message-ID: <996314.17720.qm@web62108.mail.re1.yahoo.com>


Perhaps we could try to meet up in late afternoon at Ross' scope entry - sometime before dinner - 3 PM or so, Saturday?  Either way, I'll be camping in the meadow - in a large LLBEAN tent.  Come over and say hello!

- Gil


--- On Mon, 5/18/09, Bob May <rmay at nethere.com> wrote:

> From: Bob May <rmay at nethere.com>
> Subject: Re: [ATM] Anyone going to RTMC?
> To: atm at atmlist.net
> Date: Monday, May 18, 2009, 1:56 PM
> RTMC is held each year just outside
> of Big Bear Lake, CA. just
> above Riverside in the little community of Williams at the
> Boy
> Scout Camp.? There is a sign at the entrance to the
> community.
> It is held on Memorial Day weekend from Fri. to Mon.?
> The group
> that puts it on has a contract with the Boy Scouts for
> that
> weekend and it doesn't matter the phase of the moon.
> The altitude is 7200'
> The meet is open to all and meals are served.? It will
> cost near
> $100 for the weekend and $26 for a day- no meals.
> Bob May
> 
> rmay at nethere.com
> http: slash /nav.to slash bobmay
> http: slash /bobmay dot astronomy.net
> 
> 
> _______________________________________________
> ATM mailing list http://www.atmlist.net/
> 


      

From rsackett00 at yahoo.com  Tue May 19 10:30:33 2009
From: rsackett00 at yahoo.com (Ross Sackett)
Date: Mon, 18 May 2009 18:30:33 -0700 (PDT)
Subject: [ATM] Anyone going to RTMC?
Message-ID: <598021.31316.qm@web59207.mail.re1.yahoo.com>


Sounds good!

--- On Mon, 5/18/09, Gil McFarlane <gilboastro at yahoo.com> wrote:

> From: Gil McFarlane <gilboastro at yahoo.com>
> Subject: Re: [ATM] Anyone going to RTMC?
> To: atm at atmlist.net, "Bob May" <rmay at nethere.com>
> Date: Monday, May 18, 2009, 8:26 PM
> 
> Perhaps we could try to meet up in late afternoon at Ross'
> scope entry - sometime before dinner - 3 PM or so,
> Saturday?? Either way, I'll be camping in the meadow -
> in a large LLBEAN tent.? Come over and say hello!
> 
> - Gil
> 
> 
> --- On Mon, 5/18/09, Bob May <rmay at nethere.com>
> wrote:
> 
> > From: Bob May <rmay at nethere.com>
> > Subject: Re: [ATM] Anyone going to RTMC?
> > To: atm at atmlist.net
> > Date: Monday, May 18, 2009, 1:56 PM
> > RTMC is held each year just outside
> > of Big Bear Lake, CA. just
> > above Riverside in the little community of Williams at
> the
> > Boy
> > Scout Camp.? There is a sign at the entrance to the
> > community.
> > It is held on Memorial Day weekend from Fri. to
> Mon.?
> > The group
> > that puts it on has a contract with the Boy Scouts
> for
> > that
> > weekend and it doesn't matter the phase of the moon.
> > The altitude is 7200'
> > The meet is open to all and meals are served.? It
> will
> > cost near
> > $100 for the weekend and $26 for a day- no meals.
> > Bob May
> > 
> > rmay at nethere.com
> > http: slash /nav.to slash bobmay
> > http: slash /bobmay dot astronomy.net
> > 
> > 
> > _______________________________________________
> > ATM mailing list http://www.atmlist.net/
> > 
> 
> 
> ? ? ? 
> _______________________________________________
> ATM mailing list http://www.atmlist.net/
> 

From pdebaan at hotmail.com  Tue May 19 10:34:56 2009
From: pdebaan at hotmail.com (Peter De Baan)
Date: Tue, 19 May 2009 01:34:56 +0000
Subject: [ATM] silvering reagents and airline baggage
In-Reply-To: <002401c9d81e$b9464b20$2bd2e160$@com>
References: <53764.87.255.50.71.1242372754.squirrel@webmail.xs4all.nl>
	<27CCB86E-1162-4C18-9C74-3FCF4D83D140@psu.edu> 
	<002401c9d81e$b9464b20$2bd2e160$@com>
Message-ID: <BLU137-W2096A5555D34A2EEBC439BB25B0@phx.gbl>


Was that by chance:

 







To extend the Tarnish free time of the miror, enclose the

mirror in dry paper soaked in a "Alum" solution which will 

scavence from the air Hydrogen-sulfide which causes the  

tarnissing.Peter
 
> From: mbartels at bbastrodesigns.com
> To: atm at atmlist.net
> Date: Mon, 18 May 2009 18:11:14 -0700
> Subject: Re: [ATM] silvering reagents and airline baggage
> 
> >>>
> The important part of protecting a silver mirror is keeping it from 
> sulfur. This means keeping eggs away, and avoiding coal. If you have a 
> coal furnace, don't silver in the winter. this means the local 
> environment is an issue too.
> <<<
> 
> 
> I remember John Hall from the UK using a cloth bag pressed against the
> mirror face (filled with ?). IIRC, his coatings lasted years.
> 
> Mel Bartels
> 
> _______________________________________________
> ATM mailing list http://www.atmlist.net/

_________________________________________________________________
Hotmail? has ever-growing storage! Don?t worry about storage limits.
http://windowslive.com/Tutorial/Hotmail/Storage?ocid=TXT_TAGLM_WL_HM_Tutorial_Storage1_052009

From hermit at outofoptions.org  Tue May 19 10:38:01 2009
From: hermit at outofoptions.org (hermit)
Date: Mon, 18 May 2009 21:38:01 -0400
Subject: [ATM] silvering reagents and airline baggage
In-Reply-To: <002401c9d81e$b9464b20$2bd2e160$@com>
References: <53764.87.255.50.71.1242372754.squirrel@webmail.xs4all.nl>	<27CCB86E-1162-4C18-9C74-3FCF4D83D140@psu.edu>
	<002401c9d81e$b9464b20$2bd2e160$@com>
Message-ID: <4A120D79.4090700@outofoptions.org>

Mel Bartels wrote:
> The important part of protecting a silver mirror is keeping it from  
> sulfur. This means keeping eggs away, and avoiding coal. If you have a  
> coal furnace, don't silver in the winter. this means the local  
> environment is an issue too.
> <<<
>
>
> I remember John Hall from the UK using a cloth bag pressed against the
> mirror face (filled with ?).  IIRC, his coatings lasted years.
>
> Mel Bartels
>
> _______________________________________________
>   
I have some vague memory of some kind of cloth used for silverware and a 
discussion of what was in that?

Ken Lowther

From s.truitt at hawaiiantel.net  Tue May 19 12:26:10 2009
From: s.truitt at hawaiiantel.net (Stan Truitt)
Date: Mon, 18 May 2009 17:26:10 -1000
Subject: [ATM] silvering reagents and airline baggage
In-Reply-To: <4A120D79.4090700@outofoptions.org>
References: <53764.87.255.50.71.1242372754.squirrel@webmail.xs4all.nl>
	<27CCB86E-1162-4C18-9C74-3FCF4D83D140@psu.edu>
	<002401c9d81e$b9464b20$2bd2e160$@com>
	<4A120D79.4090700@outofoptions.org>
Message-ID: <a06230908c637ca909b9c@[72.234.152.196]>

Aloha fellow Addicts,


>I have some vague memory of some kind of cloth used for silverware 
>and a discussion of what was in that?
>
>Ken Lowther

Two products common in the fine jewelry industry come to mind. The 
first when used in a sealed plastic bag is *very* effective; and 
moderately effective, even without perfect sealing, is made by 3M.
See: http://www.starstruckllc.com/pp_antitarnish_strips.php

The other is a superb brand of English polishing cloth made by 
Selyyt, which should only be used on very clean coatings. I use the 
"Universal Polishing" type unless our local volcano's SO2 exhaust has 
caused noticeable darkening.  In that case, and to adjust a silver 
beamsplitter's ratio, the "Silver Cleaning" type is necessary.
http://www.starstruckllc.com/selvyt.php
and
http://www.selvyt.com/

The Universal Polishing variant is also excellent when used to 
prepare mating surfaces for optical contacting. In fact, I find it 
necessary for optical contacting in a time efficient manner. Washing 
them degrades their performance somewhat.


Stan Truitt

From mbartels at bbastrodesigns.com  Tue May 19 13:35:08 2009
From: mbartels at bbastrodesigns.com (Mel Bartels)
Date: Mon, 18 May 2009 21:35:08 -0700
Subject: [ATM] jamming glass
In-Reply-To: <a06230908c637ca909b9c@[72.234.152.196]>
References: <53764.87.255.50.71.1242372754.squirrel@webmail.xs4all.nl>
	<27CCB86E-1162-4C18-9C74-3FCF4D83D140@psu.edu>
	<002401c9d81e$b9464b20$2bd2e160$@com>
	<4A120D79.4090700@outofoptions.org>
	<a06230908c637ca909b9c@[72.234.152.196]>
Message-ID: <004701c9d83b$3b196580$b14c3080$@com>

http://www.sciencedaily.com/releases/2009/05/090513130932.htm 

 

Mel Bartels 


From jonas.zaveckas at gmail.com  Tue May 19 15:47:15 2009
From: jonas.zaveckas at gmail.com (Jonas)
Date: Tue, 19 May 2009 09:47:15 +0300
Subject: [ATM] First time figuring
Message-ID: <4A1255F3.5000501@gmail.com>

Hello,
have question about figuring movements. I see, this is done by W
strokes. More dense in the middle or the edges according to the
requirements. Failed to find any mentioning of rotating mirror or tool.
Does figuring is done with fixed positions?

Have read that figure checking should be done at least every 10 min.
because figure can change really rapidly (my mirror is 6" pyrex, f/6.8,
cerium oxide as polisher). Does this 10 minutes should be done with
fixed positions all the time? Can not believe it actually...


Jonas

From hermit at outofoptions.org  Tue May 19 20:26:32 2009
From: hermit at outofoptions.org (hermit)
Date: Tue, 19 May 2009 07:26:32 -0400
Subject: [ATM] First time figuring
In-Reply-To: <4A1255F3.5000501@gmail.com>
References: <4A1255F3.5000501@gmail.com>
Message-ID: <4A129768.3020901@outofoptions.org>

Jonas wrote:
> Hello,
> have question about figuring movements. I see, this is done by W
> strokes. More dense in the middle or the edges according to the
> requirements. Failed to find any mentioning of rotating mirror or tool.
> Does figuring is done with fixed positions?
>
> Have read that figure checking should be done at least every 10 min.
> because figure can change really rapidly (my mirror is 6" pyrex, f/6.8,
> cerium oxide as polisher). Does this 10 minutes should be done with
> fixed positions all the time? Can not believe it actually...
>
>
> Jonas
> _______________________________________________
> ATM mailing list http://www.atmlist.net/
>   
Change positions as normal or more often.

From alaskawolfjoe at hotmail.com  Tue May 19 23:51:04 2009
From: alaskawolfjoe at hotmail.com (lance clarke)
Date: Tue, 19 May 2009 10:51:04 -0400
Subject: [ATM] Making a sub-diameter tile tool
Message-ID: <COL113-W56C4D422AD2A0430FEA3EEA85B0@phx.gbl>


I'm about to venture into machine grinding for the first time, and although I've made a number of tile tools, I've never made a sub-diameter tile tool.  Now I'm looking at a pre-generated F/5 18" blank, and I'm wondering how to do it.  Life was so much simpler when I just had to make a dam around the mirror!  

Any suggestions for the easiest and best way to proceed?

 

Thanks for any help,

Lance

_________________________________________________________________
Internet explorer 8 lets you browse the web faster.
http://go.microsoft.com/?linkid=9655582

From jeffrowe at austin.rr.com  Wed May 20 03:28:57 2009
From: jeffrowe at austin.rr.com (Jeff Rowe)
Date: Tue, 19 May 2009 13:28:57 -0500
Subject: [ATM] Making a sub-diameter tile tool
In-Reply-To: <COL113-W56C4D422AD2A0430FEA3EEA85B0@phx.gbl>
References: <COL113-W56C4D422AD2A0430FEA3EEA85B0@phx.gbl>
Message-ID: <4A12FA69.8050803@austin.rr.com>

Lance;
How about putting some saran wrap on your pregen blank.  Take a smaller 
blank, wrap your dam material around it, tape or wire it to make your 
form. Remove the smaller blank, center your form on the pregen blank, 
and pour your tool. If you don't have a smaller blank, you could route a 
plywood disc, or find a pot, cookie tin or something similar to wrap 
your dam materiel around to make your form. You will have to use care 
when you pour your hydrostone or tool materiel, that you keep good 
contact with the form, and the pregen blank, so it does not "float" 
away. Duct tape, or masking tape, might be helpful keeping your form in 
place. You could also put your tiles in the bottem of the form, double 
sided taped to the saran, or epoxy them to your new tool after the fact.
Best
JR

lance clarke wrote:

>I'm about to venture into machine grinding for the first time, and although I've made a number of tile tools, I've never made a sub-diameter tile tool.  Now I'm looking at a pre-generated F/5 18" blank, and I'm wondering how to do it.  Life was so much simpler when I just had to make a dam around the mirror!  
>
>Any suggestions for the easiest and best way to proceed?
>
> 
>
>Thanks for any help,
>
>Lance
>
>_________________________________________________________________
>Internet explorer 8 lets you browse the web faster.
>http://go.microsoft.com/?linkid=9655582
>_______________________________________________
>ATM mailing list http://www.atmlist.net/
>
>  
>


From atm_ken_hunter at yahoo.com  Wed May 20 06:09:38 2009
From: atm_ken_hunter at yahoo.com (Ken Hunter)
Date: Tue, 19 May 2009 14:09:38 -0700 (PDT)
Subject: [ATM] Making a sub-diameter tile tool
Message-ID: <201081.86203.qm@web52711.mail.re2.yahoo.com>


Simple... go to the hardware store and buy some 4 or 6 inch wide aluminum flashing. Form it around a suitable form to get the size you want, cut off the excess, wrap it around again and use some DUCT TAPE to secure the diameter you want, wipe some Vaseline or similar (very thin coating) on the inside and place the form on the face up mirror blank. After pouring the Dental Stone, just pull off the D/T and there you go...

If you can't use DUCT TAPE or WD-40 in your project, it's not worth doing!

Ken Hunter

--- On Tue, 5/19/09, lance clarke <alaskawolfjoe at hotmail.com> wrote:

> From: lance clarke <alaskawolfjoe at hotmail.com>
> Subject: [ATM] Making a sub-diameter tile tool
> To: atm at atmlist.net
> Date: Tuesday, May 19, 2009, 9:51 AM
> 
> I'm about to venture into machine grinding for the first
> time, and although I've made a number of tile tools, I've
> never made a sub-diameter tile tool.? Now I'm looking
> at a pre-generated F/5 18" blank, and I'm wondering how to
> do it.? Life was so much simpler when I just had to
> make a dam around the mirror!? 
> 
> Any suggestions for the easiest and best way to proceed?
> 
>  
> 
> Thanks for any help,
> 
> Lance
> 
> _________________________________________________________________
> Internet explorer 8 lets you browse the web faster.
> http://go.microsoft.com/?linkid=9655582
> _______________________________________________
> ATM mailing list http://www.atmlist.net/
> 


      

From rmay at nethere.com  Wed May 20 07:25:30 2009
From: rmay at nethere.com (Bob May)
Date: Tue, 19 May 2009 15:25:30 -0700
Subject: [ATM] First time figuring
References: <4A1255F3.5000501@gmail.com>
Message-ID: <001301c9d8d0$d411bfe0$8f78fea9@amd>

Figuring is just like the rest of mirrormaking strokes.  The way
to get a figure of revolution (a sphere or other such surface
which is described as a shape that is defined by a 2 axis figure
rotated about an axis) is to rotate the mirror on the tool as you
do the shaping of the surface.  The reason to check the surface
is to insure that you don't overshoot the figure that you desire.
Unfortunately, the parabolic surface that is being made by the
figuring operation isn't a stable surface because you can't move
it about without losing the contact between the surfaces.  As a
result, you have to constantly check what the shape of the
surfacce is so you can stop when you get there.  In addition,
since the surface isn't a stable surface, some parts of it will
not meet the shape desired while others will.  You have to check
the surface as a result and adjust your strokes to bring down the
high spots.  Hopefully, the shape errors will be rings about the
surface concentric on the center of the surface.
Bob May

rmay at nethere.com
http: slash /nav.to slash bobmay
http: slash /bobmay dot astronomy.net



From rmay at nethere.com  Wed May 20 07:34:46 2009
From: rmay at nethere.com (Bob May)
Date: Tue, 19 May 2009 15:34:46 -0700
Subject: [ATM] Making a sub-diameter tile tool
References: <COL113-W56C4D422AD2A0430FEA3EEA85B0@phx.gbl>
Message-ID: <002101c9d8d2$03a5d060$8f78fea9@amd>

I just put the dam of the desired size on the mirror blank and do
the pour.  If you make the stone thick, it will not tend to come
out from underneath the dam.  A bit of weight on top of the tam
(2x4 across the dam) will also assist.
Bob May

rmay at nethere.com
http: slash /nav.to slash bobmay
http: slash /bobmay dot astronomy.net



From b-hamburger at ya.com  Wed May 20 07:54:56 2009
From: b-hamburger at ya.com (Berthold Hamburger)
Date: Wed, 20 May 2009 00:54:56 +0200
Subject: [ATM] Making a sub-diameter tile tool
In-Reply-To: <COL113-W56C4D422AD2A0430FEA3EEA85B0@phx.gbl>
References: <COL113-W56C4D422AD2A0430FEA3EEA85B0@phx.gbl>
Message-ID: <014c01c9d8d4$d5d82b30$81888190$@com>

Take any ring (cake form) 2-3" thick, place it on the mirror and cast your
tool with it as you would do with an ordinary dam.

Berthold

-- 
Berthold Hamburger - Cellist/Spain
Email: behambu at artinso.com
http://www.artinso.com
http://www.astro.artinso.com


> -----Original Message-----
> From: atm-bounces at atmlist.net [mailto:atm-bounces at atmlist.net] On Behalf
> Of lance clarke
> Sent: martes, 19 de mayo de 2009 16:51
> To: atm at atmlist.net
> Subject: [ATM] Making a sub-diameter tile tool
> 
> 
> I'm about to venture into machine grinding for the first time, and
> although I've made a number of tile tools, I've never made a sub-
> diameter tile tool.  Now I'm looking at a pre-generated F/5 18" blank,
> and I'm wondering how to do it.  Life was so much simpler when I just
> had to make a dam around the mirror!
> 
> Any suggestions for the easiest and best way to proceed?
> 
> 
> 
> Thanks for any help,
> 
> Lance
> 
> _________________________________________________________________
> Internet explorer 8 lets you browse the web faster.
> http://go.microsoft.com/?linkid=9655582
> _______________________________________________
> ATM mailing list http://www.atmlist.net/


From atmer at flash.net  Wed May 20 08:26:05 2009
From: atmer at flash.net (Anthony Stillman)
Date: Tue, 19 May 2009 16:26:05 -0700 (PDT)
Subject: [ATM] Chabot
Message-ID: <505583.64905.qm@web82008.mail.mud.yahoo.com>


Will there be a Chabot telescope making workshop this Friday?  Richard? Anyone?

Anthony

From foreilly at bestweb.net  Wed May 20 22:54:31 2009
From: foreilly at bestweb.net (Francis J. O'Reilly)
Date: Wed, 20 May 2009 09:54:31 -0400
Subject: [ATM] First time figuring
References: <4A1255F3.5000501@gmail.com> <001301c9d8d0$d411bfe0$8f78fea9@amd>
Message-ID: <0E60CA4CE6A147BEB81EE283861E8725@D5GHLR11>

Bob,

That was probably the most lucid explanation of the raw mechanics of 
figuring that I have ever seen.

Francis J. O'Reilly
----- Original Message ----- 
From: "Bob May" <rmay at nethere.com>
To: <atm at atmlist.net>
Sent: Tuesday, May 19, 2009 6:25 PM
Subject: Re: [ATM] First time figuring


> Figuring is just like the rest of mirrormaking strokes.  The way
> to get a figure of revolution (a sphere or other such surface
> which is described as a shape that is defined by a 2 axis figure
> rotated about an axis) is to rotate the mirror on the tool as you
> do the shaping of the surface.  The reason to check the surface
> is to insure that you don't overshoot the figure that you desire.
> Unfortunately, the parabolic surface that is being made by the
> figuring operation isn't a stable surface because you can't move
> it about without losing the contact between the surfaces.  As a
> result, you have to constantly check what the shape of the
> surfacce is so you can stop when you get there.  In addition,
> since the surface isn't a stable surface, some parts of it will
> not meet the shape desired while others will.  You have to check
> the surface as a result and adjust your strokes to bring down the
> high spots.  Hopefully, the shape errors will be rings about the
> surface concentric on the center of the surface.
> Bob May
>
> rmay at nethere.com
> http: slash /nav.to slash bobmay
> http: slash /bobmay dot astronomy.net
>
>
> _______________________________________________
> ATM mailing list http://www.atmlist.net/ 


From camkit at mweb.co.za  Thu May 21 05:48:13 2009
From: camkit at mweb.co.za (chris forder)
Date: Wed, 20 May 2009 22:48:13 +0200
Subject: [ATM]  silvering in the 9/11 epoch
Message-ID: <4A146C8D.1010104@mweb.co.za>

Fory years ago I used to take my mirrors to a mirror making plant where 
they sprayed on the solutions to give the coating. Dominic, why do you 
not try to source a mirror making factory and see if they can put your 
mirror into the process (ensuring that thy do not go onto the next 
process which is a  paint cover to protect the layer). Alternatively, 
you should be able to find all the ingredients for silvering as per 
Amateur Telescope Making. They are:-

Rock candy (sugar?)
Nitric acid
Alcohol
Distilled water


Distilled water
Silver nitrate


Distilled water
Caustic potash


Distilled watr
Silver nitrate.

These four solutions are used in Brashear's Process for silvering mirrors.

If you wish more info re quantity etc, contact me

Chris
Cape town



From stainless_steel at suddenlink.net  Thu May 21 07:01:18 2009
From: stainless_steel at suddenlink.net (stainless_steel at suddenlink.net)
Date: Wed, 20 May 2009 17:01:18 -0500
Subject: [ATM] ATM: Nitric Acid
Message-ID: <C0FB9C9F61B84B7D81864CF55C404447@R101>



How many of you guys knew this:

Nitric acid, along with hydrazine, were the propellents for all of Wernher 
Von Braun's detailed engineering schemes, as published popularly in the 
Viking Press books on space travel that he wrote (and Chesley Bonestell 
illustrated- can't find free pictures of the Bonestell paintings on the web 
anymore; not a problem for me; I have 'em all- you want some, ask for them).

"Red Fuming Nitric Acid" (RFNA) and [just now my memory fails me for one or 
two syllables of the other chemical- "Unsymmetrical Dimethyl Hydrazine"- 
there- used an old guy memory trick [UDMH]- are used to this day in many 
rocket engine applications, including the primary engines of the Titan 
series of launchers. Including, I suppose, the launch in the not so long ago 
launch that was filmed, where the payload cannister just fell off the Titan 
III (or IV?) and the whole rig went up in flames. The fuels require no 
ignititon system, are hypergolic. Oh, yeah- Celestron Schmidt Cassegrain 
cinetheodolites are used still to track rocket launches. There: not off 
topic!

DLZ-130

P.S. Here is my inventory of Von Braun/Bonestell books:  The Exploration of 
Mars-5 copies; Conquest of the Moon-3 copies; Across the Space Frontier-2 
copies; The Conquest of Space-3 copies.

Interestingly, in America, Von Braun is still lionized as the "hero" who put 
Americans on the moon. In Europe, I am told, he is a despized war criminal, 
guilty of crimes against humanity with his V-2.

You can find the Viking Press space travel books at Abe books and Alibris. 
1949 through '56. 


From dlago at roinc.com  Fri May 22 01:21:39 2009
From: dlago at roinc.com (Dan Lago)
Date: Thu, 21 May 2009 09:21:39 -0700
Subject: [ATM] S-FPL53 Availability
In-Reply-To: <0E60CA4CE6A147BEB81EE283861E8725@D5GHLR11>
References: <4A1255F3.5000501@gmail.com> <001301c9d8d0$d411bfe0$8f78fea9@amd>
	<0E60CA4CE6A147BEB81EE283861E8725@D5GHLR11>
Message-ID: <8935CA0705DDF149B130AE1D2B055151015B6FAD6D45@roi-dc2.roinc.com>

Can anyone comment on the availability of this glass?  I see it in many designs, but wonder if it is available to ATMs and how much it would cost.  

Thanks,
Dan

From rflrs at verizon.net  Fri May 22 01:44:29 2009
From: rflrs at verizon.net (Richard F.L.R. Snashall)
Date: Thu, 21 May 2009 12:44:29 -0400
Subject: [ATM] S-FPL53 Availability
In-Reply-To: <8935CA0705DDF149B130AE1D2B055151015B6FAD6D45@roi-dc2.roinc.com>
References: <4A1255F3.5000501@gmail.com> <001301c9d8d0$d411bfe0$8f78fea9@amd>
	<0E60CA4CE6A147BEB81EE283861E8725@D5GHLR11>
	<8935CA0705DDF149B130AE1D2B055151015B6FAD6D45@roi-dc2.roinc.com>
Message-ID: <4A1584ED.2020903@verizon.net>

Dan Lago wrote:
> Can anyone comment on the availability of this glass?  I see it in many designs, but wonder if it is available to ATMs and how much it would cost.  
>   
My [somewhat old] Ohara catalog lists S-FPL53 as 14x the cost of S-BSL7.
I believe the current published value is 15.5x.  My own estimate at the time
was that S-BSL7, as the reference Ohara glass, was about 2.4x the cost of
N-BK7, the reference Schott glass.  For availability, it might be better to
check the Ohara site -- it lists S-FPL53 as being in the most frequent melt
schedule (USA):

    http://www.oharacorp.com/index.html

or (Europe):

   http://www.ohara-gmbh.com/





From richard at foucault.co.uk  Fri May 22 01:48:54 2009
From: richard at foucault.co.uk (Richard in the UK)
Date: Thu, 21 May 2009 17:48:54 +0100
Subject: [ATM] S-FPL53 Availability
In-Reply-To: <8935CA0705DDF149B130AE1D2B055151015B6FAD6D45@roi-dc2.roinc.com>
References: <4A1255F3.5000501@gmail.com> <001301c9d8d0$d411bfe0$8f78fea9@amd>
	<0E60CA4CE6A147BEB81EE283861E8725@D5GHLR11>
	<8935CA0705DDF149B130AE1D2B055151015B6FAD6D45@roi-dc2.roinc.com>
Message-ID: <18103919.20090521174854@foucault.co.uk>

Hello Dan,

Thursday, May 21, 2009, 5:21:39 PM, you wrote:

> Can anyone comment on the availability of this glass?  I see it in
> many designs, but wonder if it is available to ATMs and how much it would cost.

According to Zemax, it is made by Ohara and has status "Recommended -
Low Partial Dispersion ". It's relative cost is 15.5 meaning it is
15.5 times more expensive than BK7.

-- 
Best regards,
 Richard in the UK


From waylon at carrinter.net  Fri May 22 01:53:09 2009
From: waylon at carrinter.net (waylon)
Date: Thu, 21 May 2009 12:53:09 -0400
Subject: [ATM] Question on the initial chordal strokes
Message-ID: <1242924789.7829.16.camel@home>

First time posting from a long time Lurker.

I have decided that this will be the year I start my Scope, I am
thinking of an 8 or 10 inch f6, I plan on making a plaster of paris tile
tool. 

I have only 1 minor question before investing time and energy in making
it.


when starting the initial hogging of the mirror, I understand the
approximate 40% overhang. The rotation of mirror and tool, at random
distances in opposite directions. I understand the need to bevel the
mirror and tool

what I have a problem with is: if you slide two flat surfaces across
each other how can you do anything but cut a flat surface.

I have watched the videos on the Stellafane web page, and read
everything I can find online about it to no enlightenment.

1. Are you saying that the downward pressure on the 40 percent that is
off the tool "Flex's the mirror into a slight curve" allowing the tool
to contact the central portion of the mirror and cutting/grinding and
"tool shaping" to occur?

2. Or am I missing something like you hold the mirror on a slight angle
during the initial hogging?


thanks,

waylon


From mjc5 at psu.edu  Fri May 22 02:20:04 2009
From: mjc5 at psu.edu (Michael Coslo)
Date: Thu, 21 May 2009 13:20:04 -0400
Subject: [ATM] Question on the initial chordal strokes
In-Reply-To: <1242924789.7829.16.camel@home>
References: <1242924789.7829.16.camel@home>
Message-ID: <902DEC80-A7F9-42C9-8E63-6CE274BF06E2@psu.edu>


On May 21, 2009, at 12:53 PM, waylon wrote:

> First time posting from a long time Lurker.
>
> I have decided that this will be the year I start my Scope, I am
> thinking of an 8 or 10 inch f6, I plan on making a plaster of paris  
> tile
> tool.

Some will try yo talk you out of that, but it will work.
>
> when starting the initial hogging of the mirror, I understand the
> approximate 40% overhang. The rotation of mirror and tool, at random
> distances in opposite directions. I understand the need to bevel the
> mirror and tool
>
> what I have a problem with is: if you slide two flat surfaces across
> each other how can you do anything but cut a flat surface.
>
> I have watched the videos on the Stellafane web page, and read
> everything I can find online about it to no enlightenment.

Try looking at it from an area perspective, without any particular  
stroke involved.

place your mirror on the bottom, and the tool on the top. (this can be  
a mental experiment or drawn on paper.

Now move your tool halfway off the mirror.

Look at the tool. Look especially at the edge. The edges will have a  
lot more area covering the mirror than the center of the tool. If you  
move the tool back and forth in the long direction, more glass will be  
taken off the center of the mirror, and less off the edge due to less  
travel. More will be taken off the tool on the edges than at the  
center. All this is due to increased grinding action due to increased  
distance. The mirror will tend to become concave, the tool convex.

In real life, we rotate the tool and mirror around so that a even  
surface is created. Different strokes are used in order to take glass  
off in different areas relative to others.

Some use one stroke from start to finish, others have favorite strokes  
to use at certain times.


>
>
> 1. Are you saying that the downward pressure on the 40 percent that is
> off the tool "Flex's the mirror into a slight curve" allowing the tool
> to contact the central portion of the mirror and cutting/grinding and
> "tool shaping" to occur?

No. Flexing glass while working with it is a pretty advanced technique  
- most of the time we don't want it.


-73 de Mike N3LI -



From paul.kulyk at gmail.com  Fri May 22 02:34:30 2009
From: paul.kulyk at gmail.com (Paul Kulyk)
Date: Thu, 21 May 2009 11:34:30 -0600
Subject: [ATM] Question on the initial chordal strokes
In-Reply-To: <902DEC80-A7F9-42C9-8E63-6CE274BF06E2@psu.edu>
References: <1242924789.7829.16.camel@home>
	<902DEC80-A7F9-42C9-8E63-6CE274BF06E2@psu.edu>
Message-ID: <20090521173430.GA25989@ganymede>

The contact area is the same at the edge of the disk and the edge of the
tool.

Pressure distribution is different however.

If the weight of the glass is distributed evenly, there must be a
greater normal force near the edge of the tool (disk on the bottom) or
the glass would have a net torque on it and want to flip off.

Thank you again Sir Issac Newton.

--

Cheers, 
Paul

On 13:20 Thu 21 May     , Michael Coslo wrote:
>
> On May 21, 2009, at 12:53 PM, waylon wrote:
>
>> First time posting from a long time Lurker.
>>
>> I have decided that this will be the year I start my Scope, I am
>> thinking of an 8 or 10 inch f6, I plan on making a plaster of paris tile
>> tool.
>
> Some will try yo talk you out of that, but it will work.
>>
>> when starting the initial hogging of the mirror, I understand the
>> approximate 40% overhang. The rotation of mirror and tool, at random
>> distances in opposite directions. I understand the need to bevel the
>> mirror and tool
>>
>> what I have a problem with is: if you slide two flat surfaces across
>> each other how can you do anything but cut a flat surface.
>>
>> I have watched the videos on the Stellafane web page, and read
>> everything I can find online about it to no enlightenment.
>
> Try looking at it from an area perspective, without any particular stroke 
> involved.
>
> place your mirror on the bottom, and the tool on the top. (this can be a 
> mental experiment or drawn on paper.
>
> Now move your tool halfway off the mirror.
>
> Look at the tool. Look especially at the edge. The edges will have a lot 
> more area covering the mirror than the center of the tool. If you move the 
> tool back and forth in the long direction, more glass will be taken off the 
> center of the mirror, and less off the edge due to less travel. More will 
> be taken off the tool on the edges than at the center. All this is due to 
> increased grinding action due to increased distance. The mirror will tend 
> to become concave, the tool convex.
>
> In real life, we rotate the tool and mirror around so that a even surface 
> is created. Different strokes are used in order to take glass off in 
> different areas relative to others.
>
> Some use one stroke from start to finish, others have favorite strokes to 
> use at certain times.
>
>
>>
>>
>> 1. Are you saying that the downward pressure on the 40 percent that is
>> off the tool "Flex's the mirror into a slight curve" allowing the tool
>> to contact the central portion of the mirror and cutting/grinding and
>> "tool shaping" to occur?
>
> No. Flexing glass while working with it is a pretty advanced technique - 
> most of the time we don't want it.
>
>
> -73 de Mike N3LI -
>
>
> _______________________________________________
> ATM mailing list http://www.atmlist.net/


From brianb at myuw.net  Fri May 22 03:07:38 2009
From: brianb at myuw.net (brianb at myuw.net)
Date: Thu, 21 May 2009 11:07:38 -0700 (PDT)
Subject: [ATM] Question on the initial chordal strokes
In-Reply-To: <902DEC80-A7F9-42C9-8E63-6CE274BF06E2@psu.edu>
Message-ID: <Pine.LNX.4.43.0905211107380.10549@hur12.myuw.net>

In the overhanging position, if you press on the center of the mirror the pressure will be greatest at the center of the mirror and the edge of the tool. Increased wear will occur in the center of the mirror (and the edge of the tool) and the top disk will become concave and the bottom will become convex.
If the pressure is applied to the mirror on the edge over the center of the tool the upper disk can become convex. I've done it.


On Thu, 21 May 2009, Michael Coslo wrote:

>
> On May 21, 2009, at 12:53 PM, waylon wrote:
>
>> First time posting from a long time Lurker.
>> 
>> I have decided that this will be the year I start my Scope, I am
>> thinking of an 8 or 10 inch f6, I plan on making a plaster of paris tile
>> tool.
>
> Some will try yo talk you out of that, but it will work.
>> 
>> when starting the initial hogging of the mirror, I understand the
>> approximate 40% overhang. The rotation of mirror and tool, at random
>> distances in opposite directions. I understand the need to bevel the
>> mirror and tool
>> 
>> what I have a problem with is: if you slide two flat surfaces across
>> each other how can you do anything but cut a flat surface.
>> 
>> I have watched the videos on the Stellafane web page, and read
>> everything I can find online about it to no enlightenment.
>
> Try looking at it from an area perspective, without any particular stroke 
> involved.
>
> place your mirror on the bottom, and the tool on the top. (this can be a mental 
> experiment or drawn on paper.
>
> Now move your tool halfway off the mirror.
>
> Look at the tool. Look especially at the edge. The edges will have a lot more 
> area covering the mirror than the center of the tool. If you move the tool back 
> and forth in the long direction, more glass will be taken off the center of the 
> mirror, and less off the edge due to less travel. More will be taken off the 
> tool on the edges than at the center. All this is due to increased grinding 
> action due to increased distance. The mirror will tend to become concave, the 
> tool convex.
>
> In real life, we rotate the tool and mirror around so that a even surface is 
> created. Different strokes are used in order to take glass off in different 
> areas relative to others.
>
> Some use one stroke from start to finish, others have favorite strokes to use 
> at certain times.
>
>
>> 
>> 
>> 1. Are you saying that the downward pressure on the 40 percent that is
>> off the tool "Flex's the mirror into a slight curve" allowing the tool
>> to contact the central portion of the mirror and cutting/grinding and
>> "tool shaping" to occur?
>
> No. Flexing glass while working with it is a pretty advanced technique - most 
> of the time we don't want it.
>
>
> -73 de Mike N3LI -
>
>
> _______________________________________________
> ATM mailing list http://www.atmlist.net/
>



From rmay at nethere.com  Fri May 22 05:06:38 2009
From: rmay at nethere.com (Bob May)
Date: Thu, 21 May 2009 13:06:38 -0700
Subject: [ATM] Question on the initial chordal strokes
References: <1242924789.7829.16.camel@home>
	<902DEC80-A7F9-42C9-8E63-6CE274BF06E2@psu.edu>
Message-ID: <001e01c9da4f$a757f200$8f78fea9@amd>

Micheal, I think you meant to say put the mirror on top.
Bob May

rmay at nethere.com
http: slash /nav.to slash bobmay
http: slash /bobmay dot astronomy.net



From rmay at nethere.com  Fri May 22 05:17:49 2009
From: rmay at nethere.com (Bob May)
Date: Thu, 21 May 2009 13:17:49 -0700
Subject: [ATM] Question on the initial chordal strokes
References: <1242924789.7829.16.camel@home>
Message-ID: <002901c9da51$3788fb20$8f78fea9@amd>

First off, you really don't want to use Plaster of Paris as it
needs to be fully coated with something to prevent water from
getting into it and turning it back to mush.  Use dental stone or
an outdoor pourable stone like Hydrocal or Hydrostone or even
cement (no sand in the cement!).  With a tile tool, you want to
do the tool after you have dug a hole that is approximately
spherical into the mirror of about 80% of the final depth (the
rest of the depth will be done with the tool) with a iron tool
and the coarse grit.  A pipe end cap for a 2" pipe will do very
nicely.
For the grinding process, the important thing to look at is where
the pressure is between the tool and glass.  Where the pressure
is is where the grinding will happen.  You can rub the two pieces
together with the grit between and not get any grinding action if
there is no force between the two surfaces.  It is the pressure
that does the forcing of the grit to break the pieces of glass
off.
Also, don't forget to put a bevel on the edge of the mirror so
that the glass doesn't spall off of the edge.  You don't need too
much but a good start with a 1/16" (approx. but minimum) of a
bevel at 45* to keep the glass from spalling off.
Bob May

rmay at nethere.com
http: slash /nav.to slash bobmay
http: slash /bobmay dot astronomy.net



From mjc5 at psu.edu  Fri May 22 05:49:22 2009
From: mjc5 at psu.edu (Michael Coslo)
Date: Thu, 21 May 2009 16:49:22 -0400
Subject: [ATM] Question on the initial chordal strokes
In-Reply-To: <002901c9da51$3788fb20$8f78fea9@amd>
References: <1242924789.7829.16.camel@home>
	<002901c9da51$3788fb20$8f78fea9@amd>
Message-ID: <1A2CDE50-7B31-4C4C-82E8-7ED2E109DC9E@psu.edu>


On May 21, 2009, at 4:17 PM, Bob May wrote:

> First off, you really don't want to use Plaster of Paris as it
> needs to be fully coated with something to prevent water from
> getting into it and turning it back to mush.

Sorry Guys. I think all my advice is wrong, so I'll just go back to  
enjoying my telescopes - made the wrong way, and quit giving out  
damaging advice. Bye now!


-73 de Mike N3LI -



From ericandroberta at sbcglobal.net  Fri May 22 09:34:54 2009
From: ericandroberta at sbcglobal.net (D ERIC ALLEN)
Date: Thu, 21 May 2009 17:34:54 -0700 (PDT)
Subject: [ATM] ATM: Re: Question on the intial chordal strokes
Message-ID: <534904.78980.qm@web80504.mail.mud.yahoo.com>

If you're hogging out a mirror with an equal diameter tool, you'll want the mirror on top; not on the bottom.? The weight of the overhanging glass, even without pressure, will cause the?most wear at the edge of the tool, and the least wear at the trailing edge of the mirror.
Eric Allen

From vorblesnak at peak.org  Fri May 22 09:37:36 2009
From: vorblesnak at peak.org (vorblesnak at peak.org)
Date: Thu, 21 May 2009 17:37:36 -0700 (PDT)
Subject: [ATM] Anyone heard form Shane LaPierre
Message-ID: <3827.69.59.200.230.1242952656.squirrel@webmail.peak.org>

My emails to him are bouncing.

Sorry about the off topic post. If you have news send me an email, not the
list.

David Davis
Toledo, OR 97391




From ericandroberta at sbcglobal.net  Fri May 22 09:42:30 2009
From: ericandroberta at sbcglobal.net (D ERIC ALLEN)
Date: Thu, 21 May 2009 17:42:30 -0700 (PDT)
Subject: [ATM] ATM: Re: Question on the intial chordal strokes
Message-ID: <518056.14244.qm@web80501.mail.mud.yahoo.com>

Sorry.? I should have said "inner edge" rather than "trailing edge".? I was thinking of diametral strokes, which will also generate a curve; just not as fast.
Eric Allen

From rmay at nethere.com  Fri May 22 14:46:18 2009
From: rmay at nethere.com (Bob May)
Date: Thu, 21 May 2009 22:46:18 -0700
Subject: [ATM] Question on the initial chordal strokes
References: <1242924789.7829.16.camel@home><002901c9da51$3788fb20$8f78fea9@amd>
	<1A2CDE50-7B31-4C4C-82E8-7ED2E109DC9E@psu.edu>
Message-ID: <000601c9daa0$a1ca9300$8f78fea9@amd>

That's something that I find a bit confusing.  Make the tool your
own way.  I just noted that POP isn't waterproof so it needs to
be protected from water.
Richard's Secret Sauce and marine epoxys like the West system are
mentioned for protecting POP from the water but if you want to
make a tool from POP and don't plan on coating it, go right ahead
and learn the lessons already learned.  We've been there and
learned about those problems.
Bob May

rmay at nethere.com
http: slash /nav.to slash bobmay
http: slash /bobmay dot astronomy.net



From atmer at flash.net  Sat May 23 10:36:02 2009
From: atmer at flash.net (Anthony Stillman)
Date: Fri, 22 May 2009 18:36:02 -0700 (PDT)
Subject: [ATM] Anyone at RTMC
Message-ID: <325350.45079.qm@web82001.mail.mud.yahoo.com>


Is anyone at RTMC on line?  If so, could, would you let us know what's going on?  Please!  I'm in RTMC withdraw.

Anthony


From rozer at pacbell.net  Sat May 23 10:43:33 2009
From: rozer at pacbell.net (Richard Ozer)
Date: Fri, 22 May 2009 18:43:33 -0700
Subject: [ATM] Anyone at RTMC
In-Reply-To: <325350.45079.qm@web82001.mail.mud.yahoo.com>
References: <325350.45079.qm@web82001.mail.mud.yahoo.com>
Message-ID: <4A1754C5.8050200@pacbell.net>

Hi Anthony,

I ducked into the lounge at Camp Oaks to use the wireless and saw your 
note... 
The weather up here is great, in stark contrast to last years' 18 degree 
blizzard.
I'm a merit award judge this year... and can say that there are some 
interesting innovative entries... although only 10 so far.

Attendance is down... I'll put it this way; there was no line-up at the 
entrance gate and no jockying for camp sites.
Vendors are fewer as well... all in all I'm glad I came.

RO

Anthony Stillman wrote:
> Is anyone at RTMC on line?  If so, could, would you let us know what's going on?  Please!  I'm in RTMC withdraw.
>
> Anthony
>
> _______________________________________________
> ATM mailing list http://www.atmlist.net/
>
>   

From atmer at flash.net  Sat May 23 11:01:47 2009
From: atmer at flash.net (Anthony Stillman)
Date: Fri, 22 May 2009 19:01:47 -0700 (PDT)
Subject: [ATM] Triplet
In-Reply-To: <3183d250711090321l23b17e67y71bc7189909483f8@mail.gmail.com>
References: <3183d250711090321l23b17e67y71bc7189909483f8@mail.gmail.com>
Message-ID: <920703.73390.qm@web82005.mail.mud.yahoo.com>




S-FPL51

Alfredo,

Congratulation on your achromat.  Mine turned out not very brag-able about.  As for a triplet, I've only looked at f/12 to f/15 designs.  The radius tolerances are a lot tighter.  0.1 percent-ish instead of 1 percent-ish.  It's kind of daunting.

I'm working on a 8 inch achromat now, fl really long, f/20.  It's normal glass.  I've just always wanted one.  The cool factor.  The surface are ground.  I've got to make proof plates next. I'm also collecting carbon fiber panels for the tube.  The plan is to break the tube into three pieces for storage.  Maybe add 17th century support wires to control sag, like Bob's.

If I can find the Oslo files for the triplet designs I played around with, I'll post them. (My computers crashed twice since then, a virus that did a lot of damage.) But check the archive, I think Richard posted one.  If not, perhaps he'll design one for you (all of us).  Richard, if I may ask, please look at the tolerances and wether the last surface can be twicked to fix faults in the rest of them.  That makes it a lot more "I'm only so good" ATMable.  Its probably a boring chalange for you but please.

Anthony


From donald_clement at yahoo.com  Sat May 23 17:55:02 2009
From: donald_clement at yahoo.com (don clement)
Date: Sat, 23 May 2009 01:55:02 -0700 (PDT)
Subject: [ATM] Anyone at RTMC
Message-ID: <985764.58512.qm@web34208.mail.mud.yahoo.com>


I was at RTMC Friday and will return on Saturday morning. 

Don

--- On Fri, 5/22/09, Anthony Stillman <atmer at flash.net> wrote:

> From: Anthony Stillman <atmer at flash.net>
> Subject: [ATM] Anyone at RTMC
> To: atm at atmlist.net
> Date: Friday, May 22, 2009, 6:36 PM
> 
> Is anyone at RTMC on line?? If so, could, would you
> let us know what's going on?? Please!? I'm in RTMC
> withdraw.
> 
> Anthony
> 
> _______________________________________________
> ATM mailing list http://www.atmlist.net/
> 


      

From tj-johns at msn.com  Sun May 24 13:28:26 2009
From: tj-johns at msn.com (Tommy Johns)
Date: Sat, 23 May 2009 21:28:26 -0700
Subject: [ATM] Tommy added you as a friend on MyLife!
Message-ID: <1228209697.151453@msn.com>

Tommy Johns added you as a friend on MyLife(TM).
                Please confirm you know Tommy so we can connect you.
		
                Do You Know Tommy?

		YES - Connect with Tommy, and see who's searching for you
		http://smtp26.mail.reunion.com:80/track?type=click&mailingid=69100&messageid=9300&databaseid=1238061923&serial=1228209697&emailid=atm at atmlist.net&userid=151453&extra=&&&2002&&&http://www.mylife.com/showInviteRegistration.do?uid=294103609&invitee=atm at atmlist.net

		NO - I don't know Tommy http://smtp26.mail.reunion.com:80/track?type=click&mailingid=69100&messageid=9300&databaseid=1238061923&serial=1228209697&emailid=atm at atmlist.net&userid=151453&extra=&&&2000&&&http://www.mylife.com/showInviteRegistration.do?unsub=true&invitee=atm at atmlist.net&uid=294103609

		~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

		MyLife - Find everyone. All in one place.(TM) 

		You have received this email because a MyLife member sent an invitation to
		this email address. For assistance, please refer to our FAQ or Contact Us:
                http://smtp26.mail.reunion.com:80/track?type=click&mailingid=69100&messageid=9300&databaseid=1238061923&serial=1228209697&emailid=atm at atmlist.net&userid=151453&extra=&&&2001&&&http://help.mylife.com/

		Our Address: 2118 Wilshire Blvd., Box 1008, Santa Monica, CA 90403-5784

                Copyright (c) 2009 MyLife.com, Inc. All Rights Reserved.
	

From john_lynch2007 at yahoo.com  Sun May 24 14:00:03 2009
From: john_lynch2007 at yahoo.com (John Lynch)
Date: Sat, 23 May 2009 22:00:03 -0700 (PDT)
Subject: [ATM] spam on 
Message-ID: <369596.79208.qm@web110109.mail.gq1.yahoo.com>

To the 


      

From john_lynch2007 at yahoo.com  Sun May 24 14:01:37 2009
From: john_lynch2007 at yahoo.com (John Lynch)
Date: Sat, 23 May 2009 22:01:37 -0700 (PDT)
Subject: [ATM] spam on 
Message-ID: <509598.1660.qm@web110104.mail.gq1.yahoo.com>

To the group:
?
Please ignore previous message-accidentally sent without
completing message.
?
I received a weird email message that looked like spam
this evening, and the header message began with [ATM].
?
John


      

From atmer at flash.net  Sun May 24 14:24:20 2009
From: atmer at flash.net (Anthony Stillman)
Date: Sat, 23 May 2009 22:24:20 -0700 (PDT)
Subject: [ATM] spam on
Message-ID: <287783.2425.qm@web82003.mail.mud.yahoo.com>


It does appear that the list has been spammed.  Also, McAfee has red flagged the linked site.

>From a telescope making perspective, has anyone made a telescope out of SPAM, or least SPAM cans?

Anthony



From simo at simoivanov.com  Sun May 24 14:43:37 2009
From: simo at simoivanov.com (simo ivanov)
Date: Sun, 24 May 2009 14:43:37 +0900
Subject: [ATM] OT: spam on the atm list, was Re:  spam on
In-Reply-To: <287783.2425.qm@web82003.mail.mud.yahoo.com>
References: <287783.2425.qm@web82003.mail.mud.yahoo.com>
Message-ID: <4A18DE89.9090809@simoivanov.com>

Hi:

Actually, it appears that a list member has let a social networking site
access their addressbook and spam the list. I believe that was a mistake.

The reason the e-mail got to everyone is that the service in question
seems to impersonate their users when sending invitations out, so the
list software assumed it is a legit mail (the From address was, indeed,
the correct one).

A reminder to the members of this list, who use social networking sites
-- please be extra careful when you give these sites access to your
private information. You don't know how it is going to be used.

We will not be seeing more spam from this service.

Best,
Simeon


Anthony Stillman wrote:
> It does appear that the list has been spammed.  Also, McAfee has red flagged the linked site.
> 
>>From a telescope making perspective, has anyone made a telescope out of SPAM, or least SPAM cans?
> 
> Anthony
> 
> 
> _______________________________________________
> ATM mailing list http://www.atmlist.net/


From anishmangal2002 at gmail.com  Mon May 25 01:48:08 2009
From: anishmangal2002 at gmail.com (Anish Mangal)
Date: Sun, 24 May 2009 22:18:08 +0530
Subject: [ATM] How clear is the sky
Message-ID: <47eee29a0905240948q30f3f86fu7368c45db7b5ec9d@mail.gmail.com>

Hi all,

This question comes from a rookie ATMer who's recently made his first 8
incher and can count the number of viewing sessions (all in the city) on his
hand. How does one judge that how clear is the sky on a particular night. I
ask this because I am not sure how good my optics are (btw they should be
pretty good, coz the ronchi diagrams of the mirror were pretty good, though
not ideal). For example at 200x, I get a blurred image of Saturn. However,
looking at ground-based objects (at both day and night) forms clear crisp
images at the same magnification (200x). Is it a case of bad viewing
conditions?

Also, what comprise bad viewing conditions. Light pollution? Wind speed? I
guess light pollution degrades the image quality in general and high speed
winds blur the image. Am I correct on this?

Nearly all the days I've used my telescope on have been pretty windy, dusty,
cloudy and had mild storms (~60 Km/h wind speed) before or after the viewing
session.

Wishing clear skies to all,
Anish Mangal
New Delhi

From lopez at mv.mv.com  Mon May 25 02:28:55 2009
From: lopez at mv.mv.com (Lawrence D. Lopez)
Date: Sun, 24 May 2009 13:28:55 -0400
Subject: [ATM] How clear is the sky
In-Reply-To: <47eee29a0905240948q30f3f86fu7368c45db7b5ec9d@mail.gmail.com>
References: <47eee29a0905240948q30f3f86fu7368c45db7b5ec9d@mail.gmail.com>
Message-ID: <4A1983D7.9000205@mv.mv.com>

Anish:

This is an astonishingly good question.
Excellent.

First Saturn is going to go Edge on so the rings are getting harder to see.
The trapexium in Orion is another good test objec.

In New York City, NY in the summer, when it is hot humid and the air is 
still temperature inversion)  I saw 5 or 6 bands on jupiter with a 4" 
celestron doublet.
In New Boston, NY I have looked at Jupitre and seen nothing both a 
featureless disk on an AP180EDT F9.

The point is, that what you see depends on the night.

The best thing you can do is find an astronomy club and look through 
their telescopes.

Things that are easy to do:

wait for tube currents to go away.  you can see them in the disk of a 
way out of focus star.
align your optics.  If you don't know how get some one who knows how to 
help you.
check the seeing. look through your scope and a comparable telescope.  A 
4 inch refractor will work.

The fact that the rinchi image is good probably means seeing or tube 
currents or bad eyepiece.

You can also look at double stars.

Terrestrial views of object many miles away get degraded because of seeing.

Larry



Anish Mangal wrote:
> Hi all,
>
> This question comes from a rookie ATMer who's recently made his first 8
> incher and can count the number of viewing sessions (all in the city) on his
> hand. How does one judge that how clear is the sky on a particular night. I
> ask this because I am not sure how good my optics are (btw they should be
> pretty good, coz the ronchi diagrams of the mirror were pretty good, though
> not ideal). For example at 200x, I get a blurred image of Saturn. However,
> looking at ground-based objects (at both day and night) forms clear crisp
> images at the same magnification (200x). Is it a case of bad viewing
> conditions?
>
> Also, what comprise bad viewing conditions. Light pollution? Wind speed? I
> guess light pollution degrades the image quality in general and high speed
> winds blur the image. Am I correct on this?
>
> Nearly all the days I've used my telescope on have been pretty windy, dusty,
> cloudy and had mild storms (~60 Km/h wind speed) before or after the viewing
> session.
>
> Wishing clear skies to all,
> Anish Mangal
> New Delhi
> _______________________________________________
> ATM mailing list http://www.atmlist.net/
>
>   


From lopez at mv.mv.com  Mon May 25 02:33:40 2009
From: lopez at mv.mv.com (Lawrence D. Lopez)
Date: Sun, 24 May 2009 13:33:40 -0400
Subject: [ATM] How clear is the sky
In-Reply-To: <4A1983D7.9000205@mv.mv.com>
References: <47eee29a0905240948q30f3f86fu7368c45db7b5ec9d@mail.gmail.com>
	<4A1983D7.9000205@mv.mv.com>
Message-ID: <4A1984F4.4000908@mv.mv.com>

Actually just look at the stars.
If they twinkle then the seeing is very bad.

Lawrence D. Lopez wrote:
> Anish:
>
> This is an astonishingly good question.
> Excellent.
>
> First Saturn is going to go Edge on so the rings are getting harder to 
> see.
> The trapexium in Orion is another good test objec.
>
> In New York City, NY in the summer, when it is hot humid and the air 
> is still temperature inversion)  I saw 5 or 6 bands on jupiter with a 
> 4" celestron doublet.
> In New Boston, NY I have looked at Jupitre and seen nothing both a 
> featureless disk on an AP180EDT F9.
>
> The point is, that what you see depends on the night.
>
> The best thing you can do is find an astronomy club and look through 
> their telescopes.
>
> Things that are easy to do:
>
> wait for tube currents to go away.  you can see them in the disk of a 
> way out of focus star.
> align your optics.  If you don't know how get some one who knows how 
> to help you.
> check the seeing. look through your scope and a comparable telescope.  
> A 4 inch refractor will work.
>
> The fact that the rinchi image is good probably means seeing or tube 
> currents or bad eyepiece.
>
> You can also look at double stars.
>
> Terrestrial views of object many miles away get degraded because of 
> seeing.
>
> Larry
>
>
>
> Anish Mangal wrote:
>> Hi all,
>>
>> This question comes from a rookie ATMer who's recently made his first 8
>> incher and can count the number of viewing sessions (all in the city) 
>> on his
>> hand. How does one judge that how clear is the sky on a particular 
>> night. I
>> ask this because I am not sure how good my optics are (btw they 
>> should be
>> pretty good, coz the ronchi diagrams of the mirror were pretty good, 
>> though
>> not ideal). For example at 200x, I get a blurred image of Saturn. 
>> However,
>> looking at ground-based objects (at both day and night) forms clear 
>> crisp
>> images at the same magnification (200x). Is it a case of bad viewing
>> conditions?
>>
>> Also, what comprise bad viewing conditions. Light pollution? Wind 
>> speed? I
>> guess light pollution degrades the image quality in general and high 
>> speed
>> winds blur the image. Am I correct on this?
>>
>> Nearly all the days I've used my telescope on have been pretty windy, 
>> dusty,
>> cloudy and had mild storms (~60 Km/h wind speed) before or after the 
>> viewing
>> session.
>>
>> Wishing clear skies to all,
>> Anish Mangal
>> New Delhi
>> _______________________________________________
>> ATM mailing list http://www.atmlist.net/
>>
>>   
>
> _______________________________________________
> ATM mailing list http://www.atmlist.net/
>


From funnybone101 at embarqmail.com  Mon May 25 03:16:05 2009
From: funnybone101 at embarqmail.com (Mitchell Revalski)
Date: Sun, 24 May 2009 14:16:05 -0400
Subject: [ATM] How clear is the sky
In-Reply-To: <4A1984F4.4000908@mv.mv.com>
References: <47eee29a0905240948q30f3f86fu7368c45db7b5ec9d@mail.gmail.com><4A1983D7.9000205@mv.mv.com>
	<4A1984F4.4000908@mv.mv.com>
Message-ID: <585F21BCD3064507A2CCFBE2E8185B59@dmp>


This seems a bit broad. Stars low in the sky or bright stars such as Sirius
often twinkle even when seeing is very good. Also, stars often seem to
twinkle more in the winter when the cold cool air is less humid. Twinkling
stars definitely can be a parallel of poor seeing, but do not always mean
the seeing is poor. 

Mitchell 

-----Original Message-----
From: atm-bounces at atmlist.net [mailto:atm-bounces at atmlist.net] On Behalf Of
Lawrence D. Lopez
Sent: Sunday, May 24, 2009 1:34 PM
To: Lawrence D. Lopez
Cc: ATM list
Subject: Re: [ATM] How clear is the sky

Actually just look at the stars.
If they twinkle then the seeing is very bad.

Lawrence D. Lopez wrote:



From hermit at outofoptions.org  Mon May 25 03:42:10 2009
From: hermit at outofoptions.org (hermit)
Date: Sun, 24 May 2009 14:42:10 -0400
Subject: [ATM] How clear is the sky
In-Reply-To: <47eee29a0905240948q30f3f86fu7368c45db7b5ec9d@mail.gmail.com>
References: <47eee29a0905240948q30f3f86fu7368c45db7b5ec9d@mail.gmail.com>
Message-ID: <4A199502.1010402@outofoptions.org>

Look up what you can on star testing.  There is an excellent book 
available by former? lurking?  Dick Suiter.  Anyhow, while not directly 
related, it is part of a process.  You can tell what the "seeing" is 
like by an out of focus star image.  I forget which side of focus, but 
rapidly moving 'worms' across the out of focus view is an indication of 
air currents.  The star test tells us about much more than the optics.  
I won't go into detail because it is something that I think you will 
learn as you use it.

Ken Lowther

Anish Mangal wrote:
> Hi all,
>
> This question comes from a rookie ATMer who's recently made his first 8
> incher and can count the number of viewing sessions (all in the city) on his
> hand. How does one judge that how clear is the sky on a particular night. I
> ask this because I am not sure how good my optics are (btw they should be
> pretty good, coz the ronchi diagrams of the mirror were pretty good, though
> not ideal). For example at 200x, I get a blurred image of Saturn. However,
> looking at ground-based objects (at both day and night) forms clear crisp
> images at the same magnification (200x). Is it a case of bad viewing
> conditions?
>
> Also, what comprise bad viewing conditions. Light pollution? Wind speed? I
> guess light pollution degrades the image quality in general and high speed
> winds blur the image. Am I correct on this?
>
> Nearly all the days I've used my telescope on have been pretty windy, dusty,
> cloudy and had mild storms (~60 Km/h wind speed) before or after the viewing
> session.
>
> Wishing clear skies to all,
> Anish Mangal
> New Delhi
> _______________________________________________
> ATM mailing list http://www.atmlist.net/
>   


From lopez at mv.mv.com  Mon May 25 03:55:05 2009
From: lopez at mv.mv.com (Lawrence D. Lopez)
Date: Sun, 24 May 2009 14:55:05 -0400
Subject: [ATM] How clear is the sky
In-Reply-To: <585F21BCD3064507A2CCFBE2E8185B59@dmp>
References: <47eee29a0905240948q30f3f86fu7368c45db7b5ec9d@mail.gmail.com><4A1983D7.9000205@mv.mv.com>	<4A1984F4.4000908@mv.mv.com>
	<585F21BCD3064507A2CCFBE2E8185B59@dmp>
Message-ID: <4A199809.1000805@mv.mv.com>

I didn't know that.
I wonder what makes the stars twinkle when the seeing is good.

Larry

Mitchell Revalski wrote:
> This seems a bit broad. Stars low in the sky or bright stars such as Sirius
> often twinkle even when seeing is very good. Also, stars often seem to
> twinkle more in the winter when the cold cool air is less humid. Twinkling
> stars definitely can be a parallel of poor seeing, but do not always mean
> the seeing is poor. 
>
> Mitchell 
>
> -----Original Message-----
> From: atm-bounces at atmlist.net [mailto:atm-bounces at atmlist.net] On Behalf Of
> Lawrence D. Lopez
> Sent: Sunday, May 24, 2009 1:34 PM
> To: Lawrence D. Lopez
> Cc: ATM list
> Subject: Re: [ATM] How clear is the sky
>
> Actually just look at the stars.
> If they twinkle then the seeing is very bad.
>
> Lawrence D. Lopez wrote:
>
>
> _______________________________________________
> ATM mailing list http://www.atmlist.net/
>
>   


From b-hamburger at ya.com  Mon May 25 05:41:21 2009
From: b-hamburger at ya.com (Berthold Hamburger)
Date: Sun, 24 May 2009 22:41:21 +0200
Subject: [ATM] How clear is the sky
In-Reply-To: <4A199809.1000805@mv.mv.com>
References: <47eee29a0905240948q30f3f86fu7368c45db7b5ec9d@mail.gmail.com><4A1983D7.9000205@mv.mv.com>	<4A1984F4.4000908@mv.mv.com>	<585F21BCD3064507A2CCFBE2E8185B59@dmp>
	<4A199809.1000805@mv.mv.com>
Message-ID: <005601c9dcb0$014c6b30$03e54190$@com>

They twinkle because their starlight is passing through air bubbles of
different density that act like lenses of variable power and thus give the
observer the impression of variable brightness of starlight. Hence they seem
to "twinkle". 
Since starlight seems to be coming from infinite distance, stars are for us
point light sources and any variation of that points brightness becomes
quickly apparent. Planets are much closer and have a bigger apparent surface
area on the night sky, which greatly diminishes the effect even though it is
still present. But you won't see the moon twinkle (at least not for
atmospheric reasons ;-)

Berthold

-- 
Berthold Hamburger - Cellist/Spain
Email: behambu at artinso.com
http://www.artinso.com
http://www.astro.artinso.com


> -----Original Message-----
> From: atm-bounces at atmlist.net [mailto:atm-bounces at atmlist.net] On Behalf
> Of Lawrence D. Lopez
> Sent: domingo, 24 de mayo de 2009 20:55
> To: Mitchell Revalski
> Cc: atm at atmlist.net
> Subject: Re: [ATM] How clear is the sky
> 
> I didn't know that.
> I wonder what makes the stars twinkle when the seeing is good.
> 
> Larry
> 
> Mitchell Revalski wrote:
> > This seems a bit broad. Stars low in the sky or bright stars such as
> Sirius
> > often twinkle even when seeing is very good. Also, stars often seem to
> > twinkle more in the winter when the cold cool air is less humid.
> Twinkling
> > stars definitely can be a parallel of poor seeing, but do not always
> mean
> > the seeing is poor.
> >
> > Mitchell
> >
> > -----Original Message-----
> > From: atm-bounces at atmlist.net [mailto:atm-bounces at atmlist.net] On
> Behalf Of
> > Lawrence D. Lopez
> > Sent: Sunday, May 24, 2009 1:34 PM
> > To: Lawrence D. Lopez
> > Cc: ATM list
> > Subject: Re: [ATM] How clear is the sky
> >
> > Actually just look at the stars.
> > If they twinkle then the seeing is very bad.
> >
> > Lawrence D. Lopez wrote:
> >
> >
> > _______________________________________________
> > ATM mailing list http://www.atmlist.net/
> >
> >
> 
> _______________________________________________
> ATM mailing list http://www.atmlist.net/


From b-hamburger at ya.com  Mon May 25 05:47:35 2009
From: b-hamburger at ya.com (Berthold Hamburger)
Date: Sun, 24 May 2009 22:47:35 +0200
Subject: [ATM] How clear is the sky
In-Reply-To: <4A199809.1000805@mv.mv.com>
References: <47eee29a0905240948q30f3f86fu7368c45db7b5ec9d@mail.gmail.com><4A1983D7.9000205@mv.mv.com>	<4A1984F4.4000908@mv.mv.com>	<585F21BCD3064507A2CCFBE2E8185B59@dmp>
	<4A199809.1000805@mv.mv.com>
Message-ID: <005701c9dcb0$df8797d0$9e96c770$@com>

I forgot to mention that stars twinkle when seeing is bad. When seeing is
"good" the air tends to be very still. I guess the pilots on this list
(Mel?) will not disagree if I say that what makes stars twinkle also makes
you fasten your seatbelts on a plane trip at 30000 ft.

Berthold

-- 
Berthold Hamburger - Cellist/Spain
Email: behambu at artinso.com
http://www.artinso.com
http://www.astro.artinso.com

> 
> I didn't know that.
> I wonder what makes the stars twinkle when the seeing is good.
> 
> Larry
> 
> Mitchell Revalski wrote:
> > This seems a bit broad. Stars low in the sky or bright stars such as
> Sirius
> > often twinkle even when seeing is very good. Also, stars often seem to
> > twinkle more in the winter when the cold cool air is less humid.
> Twinkling
> > stars definitely can be a parallel of poor seeing, but do not always
> mean
> > the seeing is poor.
> >
> > Mitchell
> >
> > -----Original Message-----
> > From: atm-bounces at atmlist.net [mailto:atm-bounces at atmlist.net] On
> Behalf Of
> > Lawrence D. Lopez
> > Sent: Sunday, May 24, 2009 1:34 PM
> > To: Lawrence D. Lopez
> > Cc: ATM list
> > Subject: Re: [ATM] How clear is the sky
> >
> > Actually just look at the stars.
> > If they twinkle then the seeing is very bad.
> >
> > Lawrence D. Lopez wrote:
> >
> >
> > _______________________________________________
> > ATM mailing list http://www.atmlist.net/
> >
> >
> 
> _______________________________________________
> ATM mailing list http://www.atmlist.net/


From rmay at nethere.com  Mon May 25 05:55:09 2009
From: rmay at nethere.com (Bob May)
Date: Sun, 24 May 2009 13:55:09 -0700
Subject: [ATM] spam on
References: <509598.1660.qm@web110104.mail.gq1.yahoo.com>
Message-ID: <001801c9dcb1$ed47d640$8f78fea9@amd>

Ype, also got a post from a tommay that said he was putting me on
the MyFriend list.  Don't know who he is (unless he's a member
here) and I just threw the post away.  I don't need to be on some
silly list for any reason.  My four brothers and four sisters
know where I am on the web and they know better than to do
something like that.
Bob May

rmay at nethere.com
http: slash /nav.to slash bobmay
http: slash /bobmay dot astronomy.net



From rmay at nethere.com  Mon May 25 06:06:49 2009
From: rmay at nethere.com (Bob May)
Date: Sun, 24 May 2009 14:06:49 -0700
Subject: [ATM] How clear is the sky
References: <47eee29a0905240948q30f3f86fu7368c45db7b5ec9d@mail.gmail.com>
Message-ID: <002b01c9dcb3$8e7ec860$8f78fea9@amd>

There really is two different components to seeing things in the
sky.  Clarity of the sky itself wiht a high altitude low humidity
sky generally being an excellent sky and something like Bejing
being a pretty poor sky and cloud cover being absolutely dismal.
This (except for the clouds which basically block off the sky
completely) just make the seeing of objects harder to see.
The other thing is how disturbed the sky is.  That is from heat
causing cells of hot and cold air which disturb the direction
that the light is going.  You can see this when you do the
Foucault or Ronchi test and put you hand under the lightpath -
the view of the mirror gets all wiggly.
In addition tho, you have the quality of the mirror to deal with.
This is often the biggest problem with optics that haven't been
"professionally" judged to a high and qualititive standard.  At
your point, star testing is the way to find out how good of a
mirror you have.  In addition, defocusing a star and running it
through a Ronchi grating will also show defects in the mirror and
sky.  Non-straight lines indicate that the mirror has problems in
shape and wiggling of the lines indicates troubles in the tube
currents (around the edge of the image) and of the sky conditions
(all over the image) that you're looking at the star with.
BTW, the first time you get out somewhere that you can really see
the stars, you'll probably not be able to recognize the sky as
there are too many stars!
Bob May

rmay at nethere.com
http: slash /nav.to slash bobmay
http: slash /bobmay dot astronomy.net



From vla at copper.net  Mon May 25 07:30:42 2009
From: vla at copper.net (vladimir sacek)
Date: Sun, 24 May 2009 18:30:42 -0400
Subject: [ATM] How clear is the sky
References: <47eee29a0905240948q30f3f86fu7368c45db7b5ec9d@mail.gmail.com><4A1983D7.9000205@mv.mv.com>	<4A1984F4.4000908@mv.mv.com>	<585F21BCD3064507A2CCFBE2E8185B59@dmp><4A199809.1000805@mv.mv.com>
	<005601c9dcb0$014c6b30$03e54190$@com>
Message-ID: <000c01c9dcbf$47535e40$395af804@Handsome>

Based on the Old Greeks' belief, that stars are little holes and cracks 
letting the light from the place where gods live sneak through, 
I would hypothesize that stars twinkle when gods are moving
around, and when gods are resting, they're steady.

Vla

From lopez at mv.mv.com  Mon May 25 09:29:06 2009
From: lopez at mv.mv.com (Lawrence D. Lopez)
Date: Sun, 24 May 2009 20:29:06 -0400
Subject: [ATM] How clear is the sky
In-Reply-To: <005601c9dcb0$014c6b30$03e54190$@com>
References: <47eee29a0905240948q30f3f86fu7368c45db7b5ec9d@mail.gmail.com><4A1983D7.9000205@mv.mv.com>	<4A1984F4.4000908@mv.mv.com>	<585F21BCD3064507A2CCFBE2E8185B59@dmp>	<4A199809.1000805@mv.mv.com>
	<005601c9dcb0$014c6b30$03e54190$@com>
Message-ID: <4A19E652.4000502@mv.mv.com>

Berthold:

You missed the point of my question, He said:

    Twinkling stars ... do not always mean the seeing is poor.
    Mitchell

My question is:
    I wonder what makes the stars twinkle when the seeing is good.

So my question is:

 How can stars twinkle and not effect the seeing ?

I've never heard of this concept.
Larry



Berthold Hamburger wrote:
> They twinkle because their starlight is passing through air bubbles of
> different density that act like lenses of variable power and thus give the
> observer the impression of variable brightness of starlight. Hence they seem
> to "twinkle". 
> Since starlight seems to be coming from infinite distance, stars are for us
> point light sources and any variation of that points brightness becomes
> quickly apparent. Planets are much closer and have a bigger apparent surface
> area on the night sky, which greatly diminishes the effect even though it is
> still present. But you won't see the moon twinkle (at least not for
> atmospheric reasons ;-)
>
> Berthold
>
>   


From rflrs at verizon.net  Mon May 25 09:50:59 2009
From: rflrs at verizon.net (Richard F.L.R. Snashall)
Date: Sun, 24 May 2009 20:50:59 -0400
Subject: [ATM] Triplet
In-Reply-To: <920703.73390.qm@web82005.mail.mud.yahoo.com>
References: <3183d250711090321l23b17e67y71bc7189909483f8@mail.gmail.com>
	<920703.73390.qm@web82005.mail.mud.yahoo.com>
Message-ID: <4A19EB73.40300@verizon.net>

Anthony Stillman wrote:
>
> If I can find the Oslo files for the triplet designs I played around with, I'll post them. (My computers crashed twice since then, a virus that did a lot of damage.) But check the archive, I think Richard posted one.  If not, perhaps he'll design one for you (all of us).  Richard, if I may ask, please look at the tolerances and wether the last surface can be twicked to fix faults in the rest of them.  That makes it a lot more "I'm only so good" ATMable.  Its probably a boring chalange for you but please.
Maybe a rethinking of an oldie could be considered:

Title: trp02-17x
135 mm f/12 Triplet

Surf     Radius  Thickness     Glass   Diameter

 STO   951.9794       19.6     N-SK4        140
   2  -300.8625          7   N-KZFS4        140
   3   300.8625         17    N-BAF4        140
   4    -614283   1592.247                  140*
 IMA  -621.5592                            42.5

* High order figuring:
    3.8939921e-011*y^4 - 3.0293581e-016*y^6

The figuring on the last surface is a bit under
1/4 micron peak from a sphere. That is actually
an appreciable fraction of the sagitta itself.

The glass type of the center element is NOT KzFSN4.
If N-KzFS4 is actually available (there has been an
availability issue in the past), there will not be a
strong cost savings against a fluorcrown based triplet,
as the cost is estimated at 11x the price of N-BK7.
The advantage here, however, is that the glass is
relatively robust when compared to either KzFSN4 or
a abnormal dispersion fluorcrown.

The color correction over the g (435 nm) to r (706 nm)
range competes well with a fluorcrown based triplet.
The disadvantage here is that the spherochromatism
is 2.7 to 3 times higher.  For that reason, I cannot
recommend making the design much faster.

Visually, the design is diffraction limited over the
nearly the full field (42.5 mm diameter -- about 1.5
degrees), even if it may have to be refocused for the
field curvature mismatch between the objective and a
2" eyepiece.

I ran an experiment on this design.  The center element
is isoconcave.  Much like the traditional Newtonian reflector
or Littrow doublet, if you can be concerned with the
actual focal length only after you are done making the
objective, all the better.  With the same system requirements,