Q: I notice on my cabinet table saw that when the 10" blade comes to a stop, it has a wobble of approximately 3/16" side to side. Should I replace the bearing?
A: It’s unlikely that bad bearings alone would cause that much runout (side-to-side wobble) in a saw blade. Plus, you probably would’ve noticed a nasty whirring or grinding noise from bad bearings. Of the two things that would likely cause the wobble — a bent arbor or an un-flat saw blade — I suspect the latter. The easiest way to check this is to simply put a new saw blade on the saw, and see if it still wobbles. If not, your old blade is warped, possibly due to heat generated during heavy cutting. If the new blade wobbles, unplug the saw, remove the blade and check the arbor for runout with a dial indicator. Fix the indicator’s base to the saw table and set the plunger perpendicular to and in firm contact with the smooth part of the arbor near the threads. If the dial shows a variance of more than a couple thousandths of an inch as you rotate the arbor, then the arbor is bent and will need replacement — not a job I’d recommend that you tackle yourself. If your saw’s worth salvaging, hire a machinery repair person to do the work.