ATM Re: [atm_free] Stubborn 1/2 " edge zone

["Bob May" <bobmay@nethere.com>]

Heavy use of CeO means that the lap rolls over the mirror without affecting
anything.  You could work for hours on one small section without hardly any
work actually being done on the glass.
I tend to go in either of two different paths when dealing with TDE.
First is the TOT method where the lap is stroked over the edge of the mirror
with the center of the lap being in the 50-70% zone of the mirror.  Insure
that you put the pressure on the center of the lap rather than on the side
hanging over and the edge will soon be in compliance with the rest of the
mirror's surface.  I'll note that this method also opend the ROC of the
mirror.
The second way is to do a stroke where the mirror starts at the 1/3 point of
the mirror to the lap and ends when the centers are on top of each other.
All of the weight is on the part of the mirror that is off the lap, making
the lap work on the zone from the 50% area to the edge of the mirror.  The
hands need to be one in front of the other with the rear hand providing the
pressure while the front hand provides directional stability.
This stroke also opens the ROC so that the edge itself becomes part of the
general curve.  This stroke does have a slight problem sometimes in that
there will be a hill built in the center of the mirror but longer strokes
can take care of this as well as chordal strokes of the center of the mirror
over the edge of the lap removing the central hill.
Bob May
http://nav.to/bobmay
bobmay@nethere.com
NEW! http://bobmay.astronomy.net