RE: ATM shear in silicone pads

["Arjan te Marvelde (ELN)" <Arjan.te.Marvelde@eln.ericsson.se>]

Hi Aart,

It is sort of what i have done, only i use Al levers to reduce the 6 support points to the three collimation points. Then wood warping is no longer an issue, but the 3 Al levers still are.
See http://home.hetnet.nl/~artm/atm/draw/celltop.html
and http://home.hetnet.nl/~artm/atm/draw/boxcross.html for the drawings. 
I still need to upload the photos.

What i wander in your case is, the CTE may be similar to pyrex, but how about moisture? I'd say that for any wood this is a more severe cause of deformation?
/AtM 

> I'm now making my mirror cells out of maple, at least the parts that
> have to mate with the mirror.  Most hardwoods have a longitudinal CTE
> that's virtually the same as Pyrex, and fine maple has excellent
> dimensional stability.  For a small mirror I make a triangle frame out