To: atm{at}shore.net, sberfield{at}xbox.com
From: tkrajci{at}san.osd.mil
Reply-To: tkrajci{at}san.osd.mil


> From: "Scott Berfield" 
> Subject: ATM Mirror cell questions
>
> I have a question about the proper way to rig the triangles in a 9 point
> cell I am designing for a 12.4" mirror.

Because your mirror is 1.5 inches thick, you do not have to use 9 points of
support.  You can use six.  That avoids use of triangles.  You only have to
use beams.

> What are some good ways of
> mounting the triangles to allow them to pivot sufficiently to do the job
> of supporting the mirror evenly without slop that would allow the mirror
> to change its position as the scope turns? I am having trouble
> envisioning a joint that I am able to fabricate (no machining, please)
> that would do the job. I am looking for as simple a solution as possible
> (being a basically simple guy).

See:
http://overton.tamu.edu/aset/krajci/cell-bearing.htm
http://overton.tamu.edu/aset/krajci/cell-12-pt/cross-hinge.htm

You may want to consider making your compliant hinges out of RTV.  No
machining required.

Hope this helps,
Tom Krajci
Tashkent, Uzbekistan

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