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[ATM] Figuring questions on a 6f6.

Good morning guys,
 
Well, I'm trying to decide where to go next in figuring my 6F6 mirror.
Before I do anything rash, I think I need to consult with the experts.
 
The ideal measurements in FigureXP are 
 
0.000
0.0019
0.0038
 
The room temp is 85-87 degrees (still hot in Texas). The tool is full
sized with G73.
 
 
After about three hours of polishing I checked the figure. The edge
looked good and the mirror looked spherical. I decided to do another
hour of polishing to be safe. I then checked the figure again made the
following measurements:
 
1: 0
2: -0.014
3: -0.023
 
I decided I was high in the center but I knew that would be easy to fix.
So decided to try some parabolizing.
 
I did 10 minutes of MOT using the parabolizing stroke. I tried modified
the stroke to do some extra work around Z2 and Z3. Here were the
results.
 
1: 0
2: 0.043
3: 0.045
 
I was a little surprised at how much I actually took out of the center.
I'm guessing I went to far to the left and right. Anyway, I decided to
go with a basic 1/3 COC TOT stroke. I figured this would reduce the
correction between Z1 and Z2 and would reduce Z3. Ten minutes of 1/3 COC
TOT gave the following.
 
1: 0.000
2: 0.036
3: 0.060
 
I was happy with the reduction in correction from Z1 to Z2. I also
noticed that Z1 had a smoother transition from it's inner edge to it's
outer edge. However, I was really surprised to see the delta from Z1 to
Z3 increase. I thought the TOT would have a tendency to flatten out the
mirror. The above indicates the center became deeper.
 
I mulled this over for a while and decided to try another round of 1/3
COC TOT. My guess was that Z3's increase relative to Z1 was a temporary
dynamic in the glass. I think was wrong. Here are the results of 10
minutes 1/3 COC TOT:
 
1: 0.000
2: 0.053
3: 0.088
 
Well, I'm thinking COC TOT is not a good idea at this point. I'm just
really surprised that the center got deeper.
 
So questions:
 
1) Why did COC TOT deepen the center?
 
2) Since COC TOT does not appear to be reducing the outer zone, how
should I reduce the outer zone? A narrow W stroke with 1/2 diameter MOT?
Or maybe a wide W stroke with 1/6 TOT? How about a stick of dynamite...
 
Thanks,
 
-Anthony, Round Rock TX.
 
 
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