Bandsaw Belt Squeak

Upon start-up, my bandsaw lets out a squeal lasting about a half second, then disappearing. The mfg rep told me it is from a tiny bit of slack in the belt and nothing to worry about. In fact, he said a belt that's too tight will put more strain on the bearings than necessary, and it's better to err to the side of a tiny bit of slack. I tightened up the belt a little and it went mostly away, but now it's back.

This is a new-ish saw, so could it be just the belt stretching a little as part of the break-in, and should I it tighten it again, or not worry about it?
Maybe there is a different root cause than the belt tension?
The saw cuts well and I'm not experiencing any power issues. This is a S500p (fka MM20) btw.

Thanks, Edwin

P.S. I recall back in the day sometime automotive belts would squeal when they were dry and they would apply a dressing to resolve it. This raises another question - is it a good idea to dress the belt and maybe the tires from time to time, especially if you live in a dry climate?

It’s probably one of those annoying noises us woodworkers get blessed with. I know I’ve spent many hours chasing buzzings and squeaks that disappear on their own.
I would tighten the belts unless they are old and stretched.
Is your saw new Edwin.

It sounds like the belts is slipping slightly as the motor overcomes the inertia of the wheels and band to get them moving. If it annoys you tighten the belt slightly and see is the noise lessens. When my band saw was new, the belt was on and "tight", but when I pushed the saw with a heavy cut, the blade wold stall while the motor continued to run. Tightening the belt cured the problem and the saw seemed to have significantly more power. Obviously the factory had not properly tightened the belt.

You also might try swapping in a different brand of belt to see if that helps. And maybe try cleaning the sheaves in case they have some oil or grease on them.

In general you don't want to add any dressings or other treatments to a drive belt such as are found on band saws. If they start to crack or fray, just replace them.

No idea how old "newish" is, but a belt can get a glaze on it over time. Inspection will tell you that. I would definitely not put anything on the tires.

If it slips on startup, even though there is a lot of weight in those wheels to overcome, it will slip in any significant resawing as well and you likely won't hear it and it will get worse and glaze the belt. I would tighten it a little at the time until no sound on startup. My MM20 has never done this BTW.

Thanks to all for the responses. I will tighten up the belt a little at at time as suggested. The manufacturer provided an adjustment bolt system on the saw that makes this a fairly straightforward and controlled procedure.

BTW, the saw is about six months old and was purchased new. Thanks again,
Edwin

These bandsaw should have been designed with a 2 belt system. My Bridgewood, a Euro saw like yours, does the same thing. I tighten the belt and or apply belt dressing, but when it slips enough it's glazed and need replacing. It does not slip once running. Get some spares as you will use them. The belt is a weak link between a powerful motor and heavy flywheels.

Tighten the belt just enough so you can still roll it off a pulley.

Thanks everyone for the replies and advice. Today I tightened up the belt and the screech is indeed gone. Let's see if it comes back. While I was in the machine, I wiped out the motor shaft sheave with solvent just to satisfy myself that it is clean and free of oil or residue. So now I've started the machine a dozen times to revel in my new screech-free world. I might even cut some wood.

Coincidentally there was another post asking for advice on how to tighten the belt on a MM20 to eliminate screech on start up, so apparently I'm not alone.

Edwin

My MM20 has done this since new (2003). I have to adjust the belt about twice a year depending on how much I use the saw. Have replaced the belt 3 times. Of all the band saws I have owned and worked with over the years this one takes the most belt maintenance. I have a 14" Delta Milwaukee from the 1940's that I'm almost certain has the original belt (at least it hasn't been changed or adjusted in the 35 years I've owned it). And it sees nearly daily use.