Re: [ATM] 20" Fused Silica blank ( a bit long....)

[William Marriott <bmarriott@pacbell.net>]

Hello everyone;

I am known for rambling on....

Well, I took my blank (20" fused silica, 1.6" thick)
over to Chabot Telescope Making Workshop (CTMW) Friday
night, and of course everyone found it of great
interest.  And of course, the topics soon turned to
what kind of scope to make out of it. Initially I of
course had assumed I would just make a big Dob out of
it, probably easiest and cheapest way to go, but no
matter what, cheap is just relative. I have for years
helped many people figure their mirrors, small ones,
big ones, and have seen them end up in great finished
telescopes, but none for Bill, just sticking with my
10" Newt and the 6" MakNewt I built many years ago.
But now I have a chance to build a REALLY nice GREAT
scope, probably the penultimate of my telescope
endevors, and that I should go for it, and not make
costs the determining factor of how my telescope will
end up.

In my searches across the web, I have seen many
telescopes, and one really stands out, and can be seen
in the following link:

http://ari.home.mchsi.com/phase3.htm

I especially like the mirror cell.  While this one is
used as a prime focus astrograph, I believe the design
could be modified for use as a Ritchey - Chrétien
scope for visual  use, maybe photography down the
road.

If anyone can deal with the mild aspher of the main
mirror, and the big correction on the 5" hyperbolic
convex secondary, its me and my optical shop, I even
have a machine big enough to take a 20" piece of
glass.
F6?  F8?  f12? 

Its been a while since I have felt the excitement of
building a new bigger and better scope, I feel like
the  project manager of a great endevor, and look
forward to tapping into the huge knowledge bass we all
have built over the last 15 years. 

2 years and counting....

Bill Marriott
Woodacre, CA
VAOptical.com
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