ATM Horse shoe's and hangrenades

["Day, Jack" <jday@clinitech.net>]

Hi all,  (And Bill!)

 I did another foucault test on my 14" mirror last night.  And it is just
about there.  Only bad thing is one zone that is still in violation of
parabolization. 8o)  And the offender is the infamous Zone 1.  Right in the
center.  The center is high by about .018" if I drop the first zone to where
it belongs and move nothing else I should be well under 1/8 wave.  We ( a
friend and I) did four tests runs, two each, on two different testers.  Our
numbers all were within a couple of thousandths of each other, except for
zone one which was a tough call for both.  I tended to have about .020"
between zone one and two and he had about .012 between them.  The ideal
difference is about .034".  So here are the numbers, we are using the "tex"
program for the data reduction and the couder masks were also generated by
tex.

13.88 optical diam.
149" fl (f5.4)
moving light test stand
5 zones  The numbers below are sort of a "best middle of the road" set from
our four tests.

.034
.045
.075
.115
.140

Ok so zone 4 is a tad bit high,  that I have the fix for planed already, but
even if I ignored it, it wouldn't do much harm.  So the question is...  What
would be the best way to attack the center without screwing up the rest of
the mirror?  

Thanks,

Jack Day