Unisaw Bearings

[The Wolf]

Replaced the arbor bearings a few weeks ago and now they are making noise again. They can't be worn out already, what else could cause the noise?

[GROVER]

Its a possibility the replacement bearings might have been defective ( They might have been on the shelf long enough for the lubrication to fail.) Joe G

[Lew Hodgett]

----------------------------------------------- If you inadvertently applied a force that was transposed across the balls of the bearings during installation, you could have very easily brinnelled the bearings which would cause them to make noise and require replacement.

Lew

[dpb]

I _could_ get hit by an asteroid this afternoon, too...

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[dpb]

Was the noise gone immediately after replacement but now it's back again?

If so, I'd say you either have a severe misalignment, _way_ too much belt tension or similar problem causing a premature failure or as Lew says, screwed 'em up in the replacement process....or, the bearings weren't and aren't the noise in the first place. But, what specifically was a noise is pretty much indeterminate from here w/o knowing what it sounds like or anything else--perhaps, it's simply normal or the motor or...

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[Bill]

Ah, "brinelled" -- A material surface failure caused by contact stress that exceeds the material limit. Learn something new everyday! :)

Bill

[Leon]

Its a possibility the replacement bearings might have been defective ( They might have been on the shelf long enough for the lubrication to fail.) Joe G

More likely to have installed cheap bearings in the first place or damaged when inserting them.

[Leon]

Yeah you only want to apply force to the race that is making contact.

[The Wolf]

It was gone immediately after replacement but now is back. It's the arbor, not the motor.

Am going to pull the top soon and investigate further. There were some hairline cracks in the bracket on top of the right bearing. Don't know if this was a factor.

[marc rosen]

No sarcasm intended here, but can "too much belt tension" ever be a problem with an Unisaw? The motor's weight hanging from a pin provides tension across all three belts. Also to the original poster; I would like to know how old your Uni is and how much you use it. I am only curious because I wonder when (or if) I will be noticing any bearing wear in the next few years. Thanks, Marc

[Leon]

No sarcasm intended here, but can "too much belt tension" ever be a problem with an Unisaw?

Probably not as with use the belts will stretch out. Typically you want the initial belt tension pretty tight.

The motor's weight hanging from a pin provides tension across all three belts.

Yes but it is not the free hanging weight of the motor that provides the tension. Most cabinet saws belts are tensioned much like those on an automibile, hanging weight of the motor like that on a contractors saw is not the norm.

Now the older Unisaws may be totally different. ;~)

[Swingman]

Tensioning the belts on all Unisaurs that I've ever seen is the same, and, like you say, pretty much like those on an automobile ... belt tension is locked in with a bolt and bracket.

[marc rosen]

Hey Karl and Leon, Yes, I was not thinking properly. I had disassembled a '63 Uni and my working Uni has not been touched (if it ain't broke, don't fix it) and I can not recall all of the steps involved in removing the belts and motor. I do not recall a locking bolt but I am sure it existed and just absent from memory. I hope to refresh that memory this evening. =20 Marc

[GROVER]

You should probably wear a hard hat. Joe G