Re: [ATM] Was cellular, now Fused Silica

[Richard <cnc@cncservo.co.uk>]

Hi William,

Monday, June 18, 2007, 6:43:06 PM, you wrote:

WM> Hello;

WM> So, in my search for glass for an 18"-20" mirror
WM> blank, I have come upon an interesting piece of glass.
WM>  It is a 20" diameter piece of fused silica, but, it
WM> is only about 1.5" thick. 

That's thicker than the 20" Pyrex blanks a bunch of us are building
scopes with at the moment Bill. I used Plop to design an 18 point cell
for mine. There are plenty of people here who can drive Plop who will
help you, but we need to know radius of curvature of the finished
primary, central hole size and central obstruction (if any).

If you have a chance of that slab at a reasonable price, I'd grab it. A
bit thick though ;).

-- 

Best regards,
  Richard in the UK

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