Re: [ATM] ellips strokes

["Bob May" <rmay@nethere.com>]

    Aw, anybody can answer that.
The Gregorian secondary is nothing more than an eliptical mirror
with an e of something less than a paraboloid.  Since you have
malready made a paraboloid for the primary, the making of a
secondary is the same only less of a difference from the sphere
by the e of the secondary thatt you desire.  Take the e value and
multiply all of the results that you would expect of a paraboloid
and those are the values that you need to measure with the
Foucault tester.
Another way to play the testing game is to do the REAL Fopucault
test as devised by Leon Foucault and put the light source at one
focal point of the elipse you need and put the KE at the other
focus of the elipse.  These are nothing more than where the
primary images the light from a star and where the final focal
plane of the scope is going to be!
As to the strokes, just  don't be as agressive as you would be
for getting a paraboloid would be on the surface and you're going
to get there.
That's all there is to figuring and testing for the secondary of
the Gregorian telescope!
Bob May
Due to the large volume of SPAM thaat I'm getting, add an open
square bracket to the subject line or my spam filter will reject
your post~
rmay at nethere.com
http: slash /nav.to slash bobmay
http: slash /bobmay dot astronomy.net
Replace the obvious words with the proper character.

_______________________________________________
ATM mailing list http://www.atmlist.net/