ATM MakNewt Project/Polishing Corrector

[Bill & Tracy Marriott <btk@pacbell.net>]

I’ve gotten the corrector for the 6" Maksutov Newtonian project to 9u, 
and can seem to manipulate the sag. to +/- either side of nominal, so 
decided to go ahead and start polishing to see what way they tend to 
drift with both TOT and COT (Corrector on top?).  This is polishing on a 
Strausbaugh polishing machine.

R1 (cc) stays pretty stable with TOT, but will flatten very slowly if I 
pull the pin out a ways. With pin center over center, and a short 
stroke, it will deepen.

With COT, it really likes to increase CC quickly (its all relative, 
we’re talking about change in sag of approx. .0002" in 4  hours )

R2,convex,  has given me a pain in the rear, as I only seem to be able 
to polish it with TOT. When I try to polish, as soon as the corrector 
strokes to the side, the raised edge of the concave pitch tool crumbles, 
except with a very, very, short stroke, which produces very little 
polishing action. 

So, I have been running it with tool on top, and its slowly
polishing from center to edge, and slowly flattening R2.

Well, I wish I could say that I predicted accurately how they would move 
or not move, and that the sags were right where they should be, but, not 
the case, will probably regrind at least one of the surfaces. 

Next time, I’ll be ready.

Any comments on above appreciated, especially about polishing convex 
surfaces with concave tool on bottom.

-- 
Bill Marriott
Woodacre, Ca. USA
btk@pacbell.net

http://www.starlightoptical.com
Optical/ATM projects

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