Re: ATM Another Question from a Newbie--Mirror Figuring in the Cell

[Adam Perkins <scopeguru@yahoo.com>]

--- ScifiGuy <scifiguy@pacbell.net> wrote:
> 

> Since a small amount of deformation always occurs
> when using a large thin
> mirror, even when it is mounted in the best of
> cells, why not take
> advantage of this fact, and perform the final stages
> of polishing with the
> mirror mounted on its cell?  

Mike

The deformation of the mirror is not constant, this would work only as
long as the scope is pointed at a single altitude (i.e.-always straight
up).  The load on the back of the mirror is reduced as the tube is
tilted to view closer to the horizon.  By the time the mirror is
pointed horizontally, there is basically no weight on the support pads
on the back of the mirror.  At this point, all of the mirro's weight is
supported by the edge of the mirror.  

Thats the beauty of a cell which sits on balance arms, the weight
applied to the pads the mirror is resting on is always PROPORTIONATELY
the same.

Clear Skies
Adam Perkins
Covington, Louisiana


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