Re: ATM 1/2 in plate max diameter usefullness?

["James Lerch" <jlerch1@tampabay.rr.com>]

Hi Paul,

How about a 12" F/6 :)

I ran the numbers and it doesn't look too bad.  Sagitta of nearly 0.150", leaving 0.350" center thickness.  Ran the mirror thru plop, and with an 18 point cell, the RMS deviation seems reasonable.

Grinding the beast will be interesting, and since the blank will be nearly free, what the heck :)  Worst outcome is you throw it against a fire hydrant and start another project!


Take Care,
James Lerch
http://Lerch.yi.org/atm (My Telescope  Construction Webpage)
----- Original Message ----- 
From: "pdk" <pdk@tampabay.rr.com>
To: "atm" <atm@shore.net>
Sent: Friday, January 04, 2002 9:44 PM
Subject: ATM 1/2 in plate max diameter usefullness?


> 
> Opinions on the maximum size mirror (if any)
> you would make out of 1/2 inch plate glass?
> (ITS FREE so I am tempted to make some 
> mirrors from it)
> I am concerned it would be too flexible and
> become astigmatic during production.
> I believe I can mount it in such a way as to 
> avoid any significant deformation there.
> 
> Thanks,
> PK
> 
>