Re: [ATM] my ongoing war story (polishing and figuring)

[aki.lotjonen@phnet.fi]

Rodney Mayes wrote <rgmayes@bellsouth.net>:

> I would appreciate any good advice that any of you good folks would 
> care to offer on the figuring process.  I am using a full sized lap 
> that is beveled just enough to make the lap about 1/10 inch smaller 
> diameter than the mirror.  Since this is my first try, I am a little 
> unsure of the parabolising stroke length, amount of pressure, stroke 
> speed, how much to turn while stroking, etc.  I just try to be 
> random, follow the info that I have available, and learn as I go.
>

Rodney,

If your starting point is a good sphere with good edge (no TDE) you 
just make W-strokes with a 50% tool, so that the tool's edge just touch 
the mirror's edge (or goes a little bit over) in the ends of W-stroke. 
Use very watery cerium, just your hands weight on the tool and do app. 
15..20 min figuring work before testing. Try to concentrate to make 
smooth and uninterrupted strokes on the horizontal level. It's easy! 
This way you get closer and closer to the target. If the center get 
more correction than edge area, try to change the stroke-pattern a 
little bit and check what was the effect. If you go over you know how 
to come backwards...

I do the figuring always that way. It's just a one way.

Regards,
Aki Lötjönen
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