Re: [ATM] Mirror clips

[Mike Lockwood <melockwo@uiuc.edu>]

Jason,

How is the figuring going?

Jason Hissong wrote:
> Drawing out the plans for my 8" sphere-o-scope and I went to Home Depot 
> today to scope out materials.  I am pretty much finding what I need... 
> except something for mirror clips.  I found angle brackets, but none of 
> them have an elongated slot like I see in so many mirror clips around.  
> Is that just something you make with a drill and a file?

I swear - only serious answers here....

I try not to have ANY metal touching my optics.

I like to use small pieces of non-brittle plastic for the clips, and I 
  angle the underside so that they have the same angle as the bevel of 
the mirror.  Therefore, they only contact the mirror on the bevel, not 
on the optical surface, and I don't get marks on the coating from the 
mirror rattling against the clips.  I extend the clips 1/16-1/8" over 
the optical surface, and secure with a bolt/screw.

The overall shape of the clip ends up like:

  ---------------
|              |
|             /
|            /
|           /
  -----------

The best type of plastic for this is a type that is slightly soft, but 
is still hard enough to drill and tap.  It is not brittle type that 
will crack under pressure.  I got some white plastic at a plastic 
supply place that is a little softer than PVC.  Might be Nylon. 
Teflon would probably work, too.  Typical clip dimensions are 1/2" 
wide by 1" long by 1/2" tall, again with only a little extending over 
the mirror.  The plastic can be cut with a hacksaw or fine-toothed 
hand saw.  A sharp knife cleans up the corners/surfaces.

For you, an 8" mirror is light and the structural requirements for the 
clips will be minimal.

By the way, typically all the support points in my cells are small 
teflon pads.  That is only one way to do it, but it works for me.

	Mike Lockwood

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