New Unisaw - sounds like belt is jumping?

[Nick Mazzino]

Hi all,

I just recently picked up a new Unisaw, that I believe is from 2004. I am new to woodworking and in the process of setting up my first shop.
The Unisaw is in fairly good shape. However, when it runs after about 10 seconds it does not make a consistent sound. It sounds as if a belt is wobbling or jumping. Or possibly a bearing is bad.
Any ideas? Is the saw okay to use as is?

Please see the youtube link below for a video of the jumping sounds it is making:

https://www.youtube.com/watch?v=jGxi5tkIgbE

Thanks for all of your help!
Nick

[Ric Flanders]

Get an owners manual and go through the belt replacement procedure. My PM 66 did this and it was caused by a loose pulley set screw. Do not use as is.

[glenn bradley]

Ric is on target. Assure that everything is mechanically sound. If your "new" belts were in position since 2004 they very well could have a hump in them. There may be some way to recover them (stagger their position on the sleeves) but, I'd just replace. YMMV.

[Matt Day]

That sounds like bearings to me, either motor or arbor.

First step, remove the belts. Access from the motor opening, loosen both of the motor mount bolts and push the motor up to get some slack in the belts, tighten bolts to keep motor in place. Remove blade and remove the belts through top blade opening.

Step 2, Turn on the saw. What do you hear? If you hear screaching noises it’s the motor bearings.

Step 3, turn the arbor pulley by hand. Is it smooth or rough and crunchy feeling? If not smooth the arbor bearings are toast and need to be replaced.

Step 4, if both sets of bearings check out, the belts could have set or are out of alignment or out of adjustment. Doubtful based on your video though. My belts on my ‘55 are looser than you would expect and run very smooth without slipping.

[Marshall Harrison]

I didn't hear anything?

I guess I really fail at this. LOL

[Andrew Hughes]

I couldn't hear anything bad. Just sounds like a tablesaw.
I ran the video twice :confused:

[Matt Day]

There’s definitely some screaching in there which likely is dry or worn out bearings.

[Cary Falk]

I hear possible bad bearings as well.