Re: ATM

["Charvell" <charvell@sofnet.com>]

You know, If a post is obscure enough with a shread of truth to it and
someone (newbie) looking for good advice comes along and takes it at face
value, It could be a very bad hair day    {;o])

> Date: Thu, 23 Aug 2001 21:07:49 -0700
> From: "Richard Schwartz" <richas@earthlink.net>
> Subject: Re: ATM Silicone Glue and a UO mirror cell
>
> The problem with mirror clips is that they are not enough by themselves.
> You need to glue the mirror to a solid backing plate with epoxy, and then
> clamp the mirror clips as tight as they will go in order to keep the
mirror
> from flexing.  Be sure that the epoxy covers the entire rear surface of
the
> mirror, without any gaps or bubbles.   It is best to clamp down the
> retaining clips really tight before the epoxy has cured, so that you
squeeze
> out any excess.
>
> Besides this, the triangular load spreaders, if you have any, need to have
> their anti-rotation pins thick enough to contact the edge of the holes in
> the baseplate that they engage to prevent the triangles from rotating.
> Otherwise, the triangle plates may rotate and induce suspension errors in
> the glass.  Even worse, the centers of support will no longer be at the
> radius of equilibrium!
>
> For the best information on mirror cells and the best materials to use,
see
> John Hindle's classic 1933 paper in the three volume ATM set (now
available
> from Wilmann-Bell).
>
> . . . Richard