On Sun, 21 Jun 2009 18:04:19 GMT, "David Merrill"
wrote:

Perhaps temporarily remove your collection nozzle and replace it with a
piece of cardboard faced with a sheet of witness paper (plain white paper)
suitably mounted to the wheel shroud and perpendicular to the magnetic
chuck. If this detects the particle strikes satisfactorily, grind a variety
of materials, dress the wheel, etc with it in place. Then shape the intake
of a new collection nozzle to encompass the accumulated particle spray
pattern that has formed on the witness paper.

I like it. Perhaps some stripes of Vaseline would catch the particles
and better show the distribution of the spray.

--
Ned Simmons