Re: [ATM] my ongoing war story (polishing and figuring)

["Jerry" <wa4guu@verizon.net>]

I suggest that you verify that you are properly interpreting the tests.


It is more likely that parabolizing stroke did take you from a sphere in the
direction of a parabola. If your lap has worked well to get you to a sphere
and then you did the long W strokes that went well to the left and right it
is almost certain that you do not have a hill in the center. If you did not
go far enough to the sides then you may have put more correction on the
outer zones and left the center uncorrected. But you sure wouldn't have a
turned up edge. 


Some reasons for mis-interpretation could be.... 
Grating on wrong side of COC. 
If using Foucault, the knife cuts into the returning cone from the opposite
side compared to Foucault pictures that you are using for a reference.

No matter how sure you are.... verify.  It is the easiest action to take. If
you are wrong then you will work yourself to death, Or you will have an
Oblate sphereoid when you finish. I am not sure which would be worse.

Jerry



  Rodney Mayes <rgmayes@bellsouth.net> wrote:
    Still at it on my first mirror. It has now officially become personal.
After finally achieving a nicely polished spherical surface, I took the
plunge into figuring. I plunged right in to the hill of no return; well,
almost. I cold pressed for about an hour then began the Tex "normal"
parabolising stroke

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