[ATM] (no subject)

[mdholm at telerama.com (mdholm@telerama.com)]

>I think if I create enough problems in one mirror I will be an expert after.

Ah! Now you are working at my level!

>I am thinking for my next session to trim the lap to approx 1/4" undersized
>and lengthen my strokes to 1/3 center over center. Hopefully this will not
>touch the edge and work the middle zones to meet up with the edge and
>center. Am I on the right track here?

I know this sounds a bit crazy, but I think trimming the lap down is actually a 
bad idea for getting rid of turned edge.  Believe it or not, you actually want 
more action in the outer zones of the mirror, not less.  You don't want the lap 
larger than the mirror, because that will make a ridge in the pitch when you 
press, and that will make a turned edge, but the lap should be trimmed only a 
little smaller than the mirror clear aperture.  Of course it is possible to 
work with a sub diameter lap, but the results are not predicted as easily by 
the techniques shown in the standard references

Try TOT 1/3 COC for a while.  The center should come back up and the edge too.  
Working COC may start making zones.  If that starts, switch to a W.

Mark Holm
mdholm@telerama.com