RE: ATM Polishing/figuring advice for a newbie please?

[anthony.n.butler@bt.com]

At 21:48 1999-11-29 Jim Burrows wrote:
 
        731 nm, +3.80, long parabolizing strokes, go to the sphere and
beyond.


Thanks Jim,
Yes the "-" meant toward the mirror. I'm sorry, I should have made that
clear.
Have tried the long strokes and now I have a really smooth figure and the
raised area in the centre is gone. Progress had been slow up to this point
and so I expected to have to push a lot of glass to get anywhere after
considering how far out I thought I was.
WRONG!
I gave it 40 minutes on the lap, although with a fairly thin Ceo mix, and I
have gone too far. 
I should have taken it a lot easier as I have a hyperbola now. I just didn't
expect things to start moving that quickly.
The pertinent figures are now around (IIRC)  0.0mm (centre)     1.98mm
4.02mm  5.79mm (edge)
I will have to back up a bit. Would I use 1/3 "W"? or something shorter
still? I don't mind too much if it makes a high zone in the centre again as
I know how to get rid of it now. I'll just be more careful.

Regards,
Anthony Butler

G7JWH
Coventry, England

p.s. Beautiful hand-crafted glass ashtray for sale. Approx f7   >VBG<