Table saw arbor runout

[Tom Henderson2]

Good evening everyone.

Would you take corrective action if your table saw flange radial runout was less than 0.001 but the lateral runout (wobble) was 0.0025?

I recently brought my Father's mid-sixties Craftsman table saw home and I'm in the process of doing what I can to dial it in. I started by measuring arbor runout.

Radial runout was good -- less than 0.001 total indicated runout (TIR).

Lateral runout wasn't so good -- 0.0025 at the flange. Extrapolating out from the 1.5" flange that equates to about 0.017 at the rim of a 10" blade.

I confirmed this by mounting a master plate and checking the alignment to the slots, using a shop-made sled for the dial indicator. I took measurements with the arbor installed at 90-degree intervals; the results varied from 0.002 to 0.018 depending on the angle.

I removed the plate, cleaned up the arbor flange, washer and nut face with scotch-brite, made sure everything was clean, and repeated the process. The results were virtually identical.

With a blade installed, the runout is visible to the naked eye as the blade coasts to a stop. I tried a couple blades and got the same result.

So as I mentioned at the top, would you experienced folks take action if you measured these kinds of numbers on your saw? What do you recommend? Replacement arbors are available from Sears, but I wonder if they are made any better than what I have already...

Any thoughts are appreciated. I hope the above description makes sense.

-Tom H.
Ventura, CA

[john frank]

Tom; I'd first try new bearings on the arbor shaft. Thats more than likely where your runout is coming from.

[Phil Thien]

Have you thoroughly cleaned all the blade washers, the nut, and the flange with something like lacquer thinner and a toothbrush? Even the smallest amount of pitch that is stuck somewhere can through the entire thing off.

[Tom Henderson2]

John-

The radial (vertical) runout is so small the dial indicator barely budges -- less than 0.001. It is the lateral runout (wobble) that I'm concerned about. Is it likely that bad bearings would lead to wobble, but not radial motion?

And Phil brings up a good point about cleanliness, but I did take pains to clean everything carefully.

Sounds like I may need to look into having a machine shop true up the arbor flange. And I suppose new bearing couldn't hurt.

Anybody ever have an arbor trued up by a machine shop?

-Tom H.
Ventura, CA

[Pete Bradley]

Tom; I'd first try new bearings on the arbor shaft. Thats more than likely where your runout is coming from.

I seriously doubt that bearings are causing the runout you're describing. However, I'd still do bearings in this case because of their age. If they seize up and spin, they'll start to eat the shaft or bore, and that gets to be a much bigger job to fix. If you're not familiar with bearing replacement, check in with the forum at www.owwm.org for details. If you are, just remember that there will likely be a spring washer, spacers, and perhaps a shim or two that all have to go back in the same places.

Pete