[ATM] Mirror cell design - diagram wanted

[tkrajci at san.osd.mil (Tom Krajci)]

>From: artbianconi@blast.net

Much ranting trimmed....

>...This test is conducted while the mirror is in a position that it
will >rarely see when in use, vertical, and when the entire weight of
the mirror >is suspended from two points on the perimeter at
approximately 4 pm and 8 >pm. 

Not everyone tests that way.  Be careful setting up this straw man
argument that may not apply to that many, at least the careful and good,
mirror testers and mirror makers.

>...Then it will be placed back on that horizontal table who?s
stiffness, or >lack thereof, is the same as it was before. The mirror
will now be polished >with a mysterious collection of moves whose
consequences are predicable >only to a handful of souls....

I recommend you study the process...and learn to analyze, evaluate, and
control the variables at play...then it will get less mysterious.

>...What I simply do NOT understand is that if sagging of any mirror is
such >a concern, why isn?t that preoccupation apparent when it is being
polished, 
>especially on a dime store bench (or the generic equivalent) which has
>about as much stiffness as a Frisbee? 

Recommend searching ATM archives, using text strings such as:
- Thin mirror polishing
- Blocking pitch support
- Rotating to average out support errors into zonal errors (to prevent
astigmatism)

>I will build a super stiff cell as planned from properly oriented
Carbon >Fiber.  It will be a hundred times stiffer than a mirror of 4
times the >thickness and it will weigh almost nothing by comparison.
We'll do a star >test and see how it compares to the Bumble Bee which,
by older aerodynamic >laws, can't possibly fly.

I say again...I, for one, am interested in seeing your
drawings/diagrams/plans before you build.  If you don't have a website,
please send them to me at  tkrajci@san.osd.mil

Thank you in advance.

Tom Krajci
Tashkent, Uzbekistan


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