Re: [ATM] convex side

["Bob May" <bobmay@nethere.com>]

I'd clean off the coating on the backside.  The paint comes off
first with some paint remover and then you clean off the silver
with some chemicals.
When you get this done, you can then test the front surface
without having the back surface give you errors in appearance.
A mirror stand and Foucault tester are easy things to build.  The
Stellavane version of a Foucault tester is very easy to build as
there are no precision things to do to make it.  When I build
testers, the only real variation from the Stellafane tester is
that I make the sliders on the Z axis rod holes rather than the V
shaped pieces that the Stellafane uses.  All this does is to keep
the two pieces of the tester together when tossing it about in
the shop.  The other mod is to install a second very bright LED
off to one side so that I can use it to find where the return of
the beam is.  Peruse my site for this little addition.
When you get your tester built and used, you will see how rough
your mirror probably is and will then find the need to polish it
to a proper shape so that the light is more properly directed to
the focus.
Bob May
bobmay at nethere.com
http: slash /nav.to slash bobmay
http: slash /bobmay dot astronomy.net
Replace the obvious words with the proper character.

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