Re:ATM Cassegrain as second telescope project.

[Richard Foulk <richard@skydive1.com>]

} I've thought about trying a cass system, since my first abortive 
} attempt decades ago. Back then, I tried making the secondary out of a 
} lens that had the approximate RC required.
} 
} My biggest stumbling block was the thought of having to make one or 
} more extra mirrors just to test the system.
} One secondary testing "method" I though about using was not to test 
} the secondary at all before use. Give the primary as good a 
} paraboloid as you can achieve, then star test the secondary, until 
} the system performance is good.
} 
} Another option would be to use the Dall method to test the secondary. 
} It doesn't require making any extra test surfaces.
} 
} Frank
} -- 
} Frank Henriquez  Programmer/Analyst  Jules Stein Eye Institute, UCLA
} frank@ucla.edu   http://www.bol.ucla.edu/~frank/index.htm

I've been toying with the idea of grinding the concave inverse of
the secondary, to make it easier to test, and using that as a mold
for a carbon fiber mirror.

Just a crazy idea ...


Richard