[ATM] My First Mirror is DONE!!!

[GF]

Mitch,

Very nice job!

Was it that long? Seems like only yesterday...

Regards,

Gary Fuchs


Mitch wrote:

>My Mirror is DONE!!!
>
> 
>
>Yes, after 2 years, 2 weeks, and 3 days my 6" F/6.5 mirror is done!
>
> 
>
>I'll try and keep this reasonably short. I would like to put out my absolute
>biggest thanks to the entire ATM community. I really don't want to start
>with many names because there are simply way too many people to thank
>personally and I don't wish to leave anyone out. So all of you out there,
>you definitely know who you are if. I would though like to give an extra
>special thanks to all the great people at our bi-monthly ATM Meetings.
>Without their hands on help my first mirror story would have turned out VERY
>different. Also if any of you were ever wondering the instigator of my ATM
>fever it was started when I stumbled upon James Lerch's 8" Bino Dob page
>where he discussed grinding two mirrors in a very short time and gave me the
>confidence to try it.
>
> 
>
>So, the fruit of my labor:
>
> 
>
>The mirror has a 1/12.5 Peak-Valley Wavefront Error Rating! Strehl Ratio is
>slightly above .98. The physical surface RMS error is 5.8nm. The overall
>correction is .042, with the perfect being .048, so my mirror is only .006
>undercorrected. As general opinion goes if you must leave a mirror one way
>or the other Undercorrected is better than Overcorrected so my mirror is
>good in that respect also. 
>
>Beside the numbers, the overall mirror is very good. The edge is fairly
>good; there is a diffraction ring, though slightly dimmer on the right. The
>very last mm or two is turned slightly down, estimated to be about 1/15 wave
>or so. It is slightly accented by the fact that there is also an equally
>narrow high zone just inside it from where my TDE and TUE originally merged,
>just the tail end remnants of it. The surface is very smooth, only a very
>slight roughness/artifact detectable in the center, but it will be covered
>by the secondary. There was also no detectable astigmatism by the ronchi
>test. 
>
>So all in all if I do say so myself this is not only an excellent first
>mirror, but a very good mirror in itself!
>
> 
>
>Fun facts:
>
>  
>
>I did 194 wets of grinding total
>
>I spend a total of 41 hours polishing and figuring
>
>About 90 sets of Foucault readings were taken, many of them me practicing.
>There are a countless number of just general viewing and ronchi tests
>
>I went through about half dozen laps with Acculap and 2 with Pitch 
>
> 
>
>(Other than the amount of grinding wets none of this includes the 7 Hours,
>20 Minutes I polished for before I scratched my mirror and had to regrind)
>
> 
>
>The mirror is off to be Aluminized, and the mounting is nearly done; Just a
>few odds and ends to tie up here.
>
> 
>
>For the full story see my website:
>
> 
>
>http://www.freewebs.com/mitchsspacepics/
>
> 
>
>I'll type up a little heart warming summary of my first ATM'ing experience
>after first light,
>
> 
>
>Once again, THANK YOU ALL!!!
>
> 
>
>Mitch
>
>_______________________________________________
>ATM mailing list http://www.atmlist.net/
>
>  
>