Re: [ATM] question on edge support

["Jan van Gastel" <jhm.vangastel@wanadoo.nl>]

Fernando,

Edge support does not mean that the mirror should be supported bij the walls
of the mirrorbox or tube, felt in between or not. From your post I get the
impression that you think it does.

Edge supports should support the mirror without deforming it. I have
experimented with different kinds of edge support and my experience is, that
the piano wire support and rollerbearing support both function very well.
Others have good results using slings. See my webpage at
http://home.wanadoo.nl/jhm.vangastel/Astronomy/50cmscope/20inch_e.htm#cell
for details and pictures. An important article about the sensitivity of the
mirror for exact placement of edge supports, is Nils Olof Carlin's article
at http://web.telia.com/~u41105032/sling/sling.htm .

Jan
http://home.wanadoo.nl/jhm.vangastel/Astronomy/


----- Original Message ----- 
From: "Fernando Ruiz" <gm.ferruiz@gmail.com>
To: <atm@atmlist.net>
Sent: Thursday, September 14, 2006 6:27 PM
Subject: [ATM] question on edge support


> Hello everybody,
>
> I am new to constructing telescopes and I have plenty of questions. I want
> to make a 12.5 f/5 1.625"-thick dobsonian. I am interested in a mirror
cell
> with edege support and have some doubts about how to make it. There I go:
>
> 1. What is the edge made of? Steel, aluminum?
>    I have asked several people working steel and aluminum in my area and
it
> costs me a fortune to get an edge made of  any of these materials.
>
> 2. Can I use plywood (say 3/4+3/4+1/2)  for the edge. How wide would it
have
> to be?
>
> 3. Is the edge in contact with the mirror or should I put felt in bewteen
> them?
>
> Thanks in advance.
> Fernando.
> _______________________________________________
> ATM mailing list http://www.atmlist.net/
>

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