ATM Generator

[Anthony Stillman <atmer@flash.net>]

Pete, all,

My drill press powered grinding engine has a 1/2 inch shaft decending from
the chuck into a pillow block attached to the bench on which the drill
press sits, c-clamped in place.  From the 1/2 inch shaft I belt over to a
5/8 inch shaft, also attached to the bench and turning in a pair of bronze
swevel bearings in blocks.  The swivels help a bit in alligning this shaft
which has at its business end, an arbor with a 1/2-20 thread.  Its true
there is a side load on the drill press chuck.  A second pillow block on
the 1/2 inch shaft would no doubt minimize this, but I'm working mostly
with stuff I've already got and both of the other 1/2 inch pillow blocks
are needed in the table.

The table is well under way.  A total reduction of 7:1 (1.5:3 then 2:7)
will drop the 150 rpm of the Bodine to ~21 rpm.  This is a bit faster than
I would like, but good enough for now.

I've really only reading and gut feeling to help me with my guesses about
rates.  The way I see it, in the most extream case, a little less than 12 *
3.14 inches  of glass pass under the tool face durning a table revolution
or 37.7" in 2.857 sec.  If I use the wall of the generator tool which is
1/8 " thick then, I've got 301.6 walls per 2.857 sec, or it takes 0.01 secs
for the glass at the edge of the blank to move one wall thickness.  It the
tool is rotating at 120 rpm, 2rps, then the tool rotates .02 revs per wall
transite, that is 1/50 revolution, 7.2 degrees of turn in the tool per tool
wall thickness trancite over the edge of the blank.  Since the tool in 6"
in diameter, approxamately (6*3.14/50) 0.017" of tool face  0.125" wide
engages (37.7*0.01/2.857) 0.132" of blank about 0.017" wide.  I think the
tool will be skipping along too fast with this table speed, but I don't
want to run the tool more than 150 or 180 rpm to hold down heating and I
don't have a larger belt gear to use in the table box currenty.  In any
case I'll try it on plate glass and adjust things before committing optical
material.

?Has anyone on the list generated before?  If so, I'de like to hear what
you have to say on drive rates, grit feeds, heating, and suck.

Anthony