Re: [ATM] Mirror cell design

[Wouter van Reeven <wouter@van.reeven.nl>]

Hi Nils,


Thanks for the reply!

On  0, Nils Olof Carlin <nilsolof.carlin@telia.com> wrote:
> The flotation cell, whether by Kriege/Berry or further refined with Plop,
> won't be a real problem. The plugs on that page may work for a really thick
> mirror, but not likely for a thin one.

Yeah I already suspected this. Thanks for pointing it out though.

> The best solution *I* can think of is here:
> 
> http://w1.411.telia.com/~u41105032/sling/threepart.htm
> 
> - it ought to work up to a maximum tube/cell rotation of +-45 deg from
> neutral - I leave it to you to figure out if that would leave any part of
> the sky inaccessible to you (if so, you could perhaps extend the 90 deg
> elements to 120 deg and overlapping, giving you +-60 deg - perhaps worth
> thinking of a bit more). But I haven't actually tried it on an eq mount, so
> I can't make any promises.

This looks familiar. You didn't post this link here a few days ago did
you? If so, sorry, I didn't have a closer look then :)
The idea of this support is clear. When the mirror is close to being
vertical, not much support to the sides is needed. As soon as the mirror
gets tilted enough it gets in need of support to the side (now facing
down) and this support must be constant over the complete lower side of
the mirror.
So, is there an alternative to using slings? I suppose creating a ring
around the mirror would not leave enough room for the mirror to expand
under heat, right? How about putting a rubber ring inside a metal ring?
Wouldn't that give enough support and not too much friction?


Thanks, Wouter van Reeven

-- 

Black holes are where God is dividing by zero.
_______________________________________________
ATM mailing list http://www.atmlist.net/