Re: ATM f/ what ...my name is

[Anthony Stillman <atmer@flash.net>]

First, thanks all for the comments both on and off line.

After reviewing the options for this piece of glass, I find I agree with
Mike L.  The Houghton is easier to fabracate, but there is something
inherently evil in turning an uncommon piece of glass into two common
pieces of glass.  So Maksutov it is.

Since I really want a visual instrument with high magnifacation and good
eye relief, and after a review of issues pertaintent, I have settled on f/
long.  This pushes me toward a Mak-Cass.  All that is left are the
specifics of the design.

One concern I have is flexure of the miniscus.  To deal with this the
curves should be shallow and the element thick.  This spelled Rumak to me.
I played around with various self generated designs, optimising in OSLO LT,
but at no time did I even come close to the performance of the design
prescribed in "Telescope Optics."   However, if anyone wants to propose a
Mak prescription which beats the performance of the "Telescope Optics"
Rumak, I'll change my plans.  Besides, I'm thinking at least 8 months just
for the corrector.

The only draw back, the about 1/2 inch of excess glass I must remove from
the blank is more than what is needed to dispose of the surface defects
near the edges.  I guess only amateurs worry about wasting CT.

Question?

With my apologies to Ike, as my arms are more unlike what they were than
they have ever been, has anyone successfully implemented the drill press
curve generator described in "Advanced Telescope Making Techniques" Volume
2?  If so, would you be willing to discuss your pitfalls and triumphs?

Anthony