Table saw problem

[Vic Baron]

I have an old Sears Contractor saw circa 1955 that I've been using trouble free for many years. I have a WWII blade with stiffener and a link belt, etc. All has been well in woodcuttingland. Then - I decided to cut an additional zero clearance insert for a thicker blade that I use occasionally. All I did was remove the WWII and the balance plate, remove the old ZCI, install the new blade without the balancer and slowly raise the blade through the ZCI. All was well.

Reversed the procedure so I had the WWII and balancer installed. Fired up the saw and gat one helluva vibration. Seems the link belt was vibrating pretty badly. Thought that by raising the blade to full height to cut the ZCI, I might have stretched the link belt ( do they stretch?) so I removed a link and tried again. Same problem - I can see and feel the link belt bouncing. Usually I just leave the weight of the big motor to keep the belt taught but something isn't right. I'll try removing additional links but wondered if anyone has run into this before. AS I said, prior to my ZCI cutting, the saw hummed.

Thanx,

Vic

[Vic Baron]

I didn't but I also ran the saw with no blade at all and the vibration in the link belt was the same. The arbor was turning smooth and level. Mt guess is something with the belt.

But I'll play with the plate anyway .

Thanx

[Courtney Mainord]

[Unisaw A100]

It maybe just occurred to me but is the belt running in the right direction?

If not, don't feel bad. The Dork Police won't be told onna 'count of we've all done something similar, once.

UA100

[Courtney Mainord]

[Unisaw A100]

By the way, I've just consulted the ancient text (Power Tool Maintenance by Daniel Irvin) and he has this to say about tension (I'm paraphrasing):

The lowest tension at which a belt will not slip under full load is best. Too little tension causes belt slapping and slippage; too much tension causes belt vibration, sheave (pulley) wear and bearing wear.

It goes without saying that the two pulleys should be checked for alignment.

UA100

[<redd103]

Did you mark the radial position of the old blade to the to the old balance plate? If not try rotating the balance plate till you get the results you want.

Wendell

[Vic Baron]

LOL! That occurred to me too so I went on a website and double checked. All was ok. solved the problem - went to Rockler and bought a new set of links. Installed new belt and all is well. Looked really close at the old belt and saw that there was a gouge along one edge. I think when I ran the saw to the full height for the ZCI, I might have overdid it and made the belt brush against something. Anyhow, the news belt isn't vibrating so all is well.

Thanx!

[Unisaw A100]

This sounds like your pulleys are too far to one side. You'll probably want to correct this.

UA100

[Vic Baron]