From: "Russell Jocoy" 
To: bobmay{at}nethere.com, atm{at}shore.net
Reply-To: "Russell Jocoy" 






>From: "Bob May" 
>Reply-To: "Bob May" 
>To: "atmlist" 
>Subject: Re: ATM 9"x5/8" mirror ..Ronchi pre-test
>Date: Tue, 29 Apr 2003 10:59:21 -0700
>
>The Ronchi grating and slit test at the ROC is indeed emulating the
>Foucault
>test.  Usually the edges on the grating are not as sharp as a knife edge so
>they tend to be a bit softer in the resulting image than a good sharp knife
>edge.
>The CeO on a pitch lap will eventually work its way into the pitch and thus
>lose its effectiveness.  This means that you can indeed start using rouge
>and get a nice surface.  I'd clean the loose CeO off of the lap with some
>detergent to get it to lift well before using the rouge thos so that the
>transition in effect happens faster.  I do it this way when it becomes
>necessary to smooth out a surface at the mirror making class and the
>surfaces clean up in about a half hour.
>Bob May
>http://nav.to/bobmay
>bobmay{at}nethere.com
>NEW! http://bobmay.astronomy.net
>
>
>
("atm{at}shore.net")

        Bob,

  Thank you for your information and knowledge on my questions. I made my
pitch lap over the weekend
and I used a latex mold to form the surface. Two sides have about 1/4"
voids, do I need to fill these with pitch?  I think it would be overkill.
Also I noticed after the fact (it's always that way sometimes) I am
only about 3/16" off center with my squares. Did I screw up, is this
too close to the center. You might know if I tried to center it it would be
farther off than that.. What luck.   My
squares are a little thick, about 3/8" thick. I am using Gugoltz #64,
I live in south Florida, it seems very brittle. Oh and this stuff is
messy..
                                                               Thanks
again... RUSS JOCOY
("atm{at}shore.net")

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