You might also try running the blade backwards from it's current
orientation. It obviously has a resonant issue since it only does it at
certain speeds. I doubt it the pivot has much to do with it.

You might also want to take some scrap steel and do a lightweight cut on
it to true up the wheel.

Jon Danniken wrote:
"RoyJ" wrote:
I've had problems with various blades. Some run much truer than others.
I'm surprised the Norton is giving you problems. You might try remounting
the wheel, perhaps giving it a slight spin from where it is now.

Thanks for that, Roy, it made a difference. Make sense, there's enough slop
in there between the wheel and the arbor.

I also noticed that the hinge pin supporting the motor goes through a hole
that feels a bit too big. I'm starting to think it might be a magnifier of
sorts when the blade's imperfection is noticable, giving it a pivot point to
translate into a sway that is perpendicular to the plane of the wheel. I'm
guessing better quality saws might have a more precise hinge at that point
than a pin and a hole through a cast yoke.

Jon