Re: ATM Battle of the bulge continues.

["Bill T." <twentiethwave@hotmail.com>]

>Current stroke is a wide "W" Stroke with a 12.5" lap TOT.
> Center overhang on middle stroke is about 4 - 5 inches shortening as I
> approach the edge.  I think tomorrow (Today I guess since it is after
> midnight...) I will re-channel the lap and warm press it with the nylon
> netting again.  Let me know if any of you have suggestions!
> Thanks,
>
> Jack Day
>
Jack,

Working TOT with that almost full sized 12.5" lap, it may be difficult to
get the center of your 13.85" f5.4 mirror deep enough.  Full sized TOT is
very effective for adding correction to the edge, but tends to leave a big
undercorrected area in the center of the mirror.

You might try some MOT, with wide W strokes -- this is a classic
parabolizing technique for equal sized mirrors and tools.  This both
flattens the edge and digs out the center -- it moves you in the direction
of a parabola.  When the lap is smaller than the mirror the center of the
mirror gets most of the effect.   When the mirror is at the end of a stroke,
its center gets strongly "cut" by the edge of the lap  -- it's kind of like
Texereau's "accented pressure" method, but upside down. This is a very
efficient stroke -- go easy at first.  Press often.  Don't apply any
deliberate accented pressure.

Whether MOT or TOT keep an eye out for a zone at about the circumference of
the lap -- best way to avoid this is not to go too many consecutive spells
either way.

Bill Tondreau