From: "CSC" 
To: "Atm" 
Reply-To: "CSC" 


Jerry:

I have a bunch of supplies from our mentor's optical lab, where he
routinely blocked optical pieces and polished mass quantities, usually to
1/10 wave. You will need some blocking wax to cement and HOLD the pieces on
the runner.

If you decide to do this project, I'll send you some blocking wax.


Sounds like fun.  Basically you need to attach the diagonal and the
surrounding scrap pieces to a backing block, something real rigid, like a
small mirror blank, and leave it in there until you get them all ground and
polished.
-----Original Message-----
From: owner-atm{at}shore.net [mailto:owner-atm{at}shore.net]On Behalf Of Jerry
B. Hillman
Sent: Wednesday, July 02, 2003 7:53 PM To: atm{at}shore.net
Subject: ATM secondary mirrors



Hi all,
Vladimir has challenged me to make the diagonal for this mirror. Actually,
he questioned why I am buying one rather than make one.  Having read horror
stories of how hard it is to make a diagonal, I had more or less decided it
wasn't worth the effort.  Now, having thought about it all day, and doing
internet research on the subject, I am asking myself, Why not?? I have some
5/8" thick glass that is the top of a small side table. Considering
how expensive good diagonals are, and considering I can have it coated at
the same time I coat my primary for no additional cost, it makes sense to
give it a try. I'll wind up with a better one than I can buy anyway, and
without any additional cost to myself. I already have all the necessary
grinding and polishing supplies, and the glass to boot. I'll be star
testing the scope again tonight, so I'll have a chance to do the Ronchi
test also.  I am going to spend some extra time to make sure the scope is
properly collimated (Thank you Nils Olof Carlin for a very informative
desertation on the subject ) and check everything else I can to make sure
all is in proper working order. I highly recommend Nils FAQ on the subject
of collimating a telescope. It makes things very clear on the how and why
of collimating a scope.
Clear skies, Jerry

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