"Leo Lichtman" wrote:

The fact that it occurs as the saw is speeding up, AND when you slow it
down by loading it suggest that it is a resonant condition. I'm not sure
how you can correct this, except maybe attach some weights to the saw.
(Doesn't sound too practical, does it?)

It's possible, that, as Roy J suggested, the wheel may be out of balance,
contributing to the problem. Rotating the wheel, as he suggested,
recentering it, or trying a different wheel might be worthwhile. I was
able to balance a fan, once, by holding a vibrating engraving tool against
it while it was not running. The vibration overcame the friction in the
bearings, and the heavy blade slowly drifted to the bottom. If you have
an engraver you might try this trick. Or maybe a Dremel tool with an
unbalanced stone or burr would work.

Thanks Leo. After I get the wheel as good as I can, I might put some shot
in the recess to see if that stiffens it up a bit.

Here's a pic of what I think the culprit is, the sloppy hingepin holes:
http://danniken.home.comcast.net/~da...44829Hinge.jpg

I don't know how shiny I can get this turd, but I wonder if putting an epoxy
concoction in the hingepin holes might stiffen it up a bit.

Jon