[ATM] 4" Pyrex, back after 10 years of gathering dust

[Francis J. O'Reilly]

Alright boys, settle down.

Let's have peace in the kingdom.

Francis
----- Original Message ----- 
From: "Richard Schwartz" <richard1941 at gmail.com>
To: "Scope Builder" <scopebuilder at gmail.com>
Cc: <atm at atmlist.net>
Sent: Friday, October 30, 2009 1:16 PM
Subject: Re: [ATM] 4" Pyrex, back after 10 years of gathering dust


>I have been polishing for a whole hour on this 12", but cannot correct  the 
>figure-- a badly pitted deep central area surrounded by glass that  is not 
>ground at all.  I cant get the tester to work at all.  I tried  to measure 
>the focal length by wetting the mirror, but could not focus  the sun at 
>all.  At least the sagitta is correct.
>
> Does the Sharpie test wrok on a pitch lap, and does it correct my  figure? 
> How do enter Sharpie test data into Sixtests software?
>
>
> Sent from Richard's iPhone
>
> On Oct 29, 2009, at 13:35, "Scope Builder" <scopebuilder at gmail.com> 
> wrote:
>
>> ----- Original Message ----- From: "Francis J. O'Reilly" 
>> <foreilly at verizon.net
>> >
>>> I never test figure until I am finished polishing. The pencil test, 
>>> sharpie test and other tests seem to be a waste of time to me.
>>
>>
>>
>> Hi, Francis.
>>
>> At your level of experience, I'd agree with you about not worrying  about 
>> the
>> figure prior to polishing.
>>
>> But.... ;-)
>>
>> In assisting with instruction at mirror classes over the last few  years,
>> I've found that tests like the sharpie test give a novice mirror  maker a
>> quick and simple method to get positive feedback that they are doing  ok.
>> It's an incredible anxiety mill for a lot of newbie mirror makers to 
>> work
>> for hours and hours without knowing whether things are going well or 
>> not.
>>
>> For newbies, 2 minutes of sharpie test can remove hours of potential 
>> anxiety
>> which could cause the mirror maker to start second guessing things  they
>> might be doing correctly.  They will know that they are doing ok, or 
>> they
>> will know that they need to do something different.  Either way,  that 
>> simple
>> answer is good to them.  Not perfect... but good. ;-)
>>
>> In my opinion... if anyone out there prefers to do sharpie or pencil
>> tests... Go For It!!!
>>
>> We, as advice-givers, should never snub the small stuff.  Those are 
>> often
>> the tools that build the confidence needed for many to persevere and  get
>> their mirrors done!  And *that* is the ultimate goal.
>>
>> - Dave
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