ATM 19th Nervous Breakdown

["Bob Walker" <tac@i1.net>]

Little known fact--the Rolling Stones are ATM's. Consider the lyrics to
their song 19th Nervous Breakdown: "Nothin I do don't seem to work/ it only
seems to make matters worse/..."    Figuring my 16" f/5.4 is not proceeding
well. After having my error in entering my data into Sixtests pointed out, I
have made numerous (19, to be exact) attempts to better the figure with
almost no results.  I would really appreciate it if one (or more!) of you
experts would take a look at my Sixtests data and suggest a course of
action.  I've tried...well, I don't want to prejudice your opinions, so I'll
just say that all my efforts have been with a 12" lap weighing 15 lbs, with
the mirror on the bottom.  I see a good figure of revolution, so whatever my
problems, I don't think they are a result of my polishing stand.  Here's the
data from the most recent polishing session:  ROC 4425.9, Couder mask zone
center diameters ( from Nils Olof's fantastic web site--thanks, Nils Olof!)
Center obstruction: 1%, (20.32 mm radius), Z1: 57.414
 *  Best regards, Bob Z2: 102.43, Z3: 131.76, Z4: 155.557, Z5: 171.136, Z6
194.539.  Moving Source.  Test Data: Z1: 0,  Z2:  -.127,   Z3: -.0762,
  Z4: -.508,   Z5: 2.64,  Z6: 3.302.  All measurements in millimeters (yes,
the Zone 2, 3, and 4 measurements are negative-closer to the mirror than
Zone 1).  If I'm reading the results correctly, I've got a trough at 5" out
from the center, a ridge at 7" out, and a turned down edge.  Is this
correct? And if so, what do I do about it?  The Ronchi bands (at .3" inside
ROC  are nearly straight across the major portion of the mirror, turning
sharply inward about 1" from the edge.  With nine bands showing, the inner
four have this shape, and the outer four - which are entirely within 1" of
the edge, curve smoothly convex (compared to the straight center line).   If
anyone cares to tackle this analysis, I would really appreciate it.  I just
don't know how to proceed.  The TDE and ridge at 7" have persisted through
all my efforts.  I'm not quite ready to use the Fire Hydrant Solution just
yet, but it's becoming less unthinkable.  I'd appreciate it if anyone who
cares to reply copy me offlist--I get the Digest version, and I would like
to apply any suggestions I get yet tonight.  Thanks to all.


P.S.  I use a 9V battery to power my tester light, and just leave one
connector connected on the clip.  I then turn it on by rotating the battery
so it contacts the other connector.  Suppose Lerch could design a stepper
motor to do that for me?

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