Squeaking in Powermatic 3520C belt/pulleys?

[Jon Rista]

I purchased a Powermatic 3520C in February 2022. It arrived a few weeks later, but I wasn't able to set it up for a few months due to space limitations, and I eventually sold my Laguna to make space. Since setting it up, the only noise the lathe has ever made is the sound of the motor, mostly at higher speeds where it gets a bit noisy (I guess the motor is designed to suck in air to cool things down.)

I haven't turned since spring, and started turning again over the last few days, and I've noticed that there seems to be a squeak in the pulleys or belt now. I've never heard it before. I had loosed the tension on the pulley back in, mid may I think it was, since I figured I wouldn't be able to turn for a while. I've been adjusting the tension to see if that would help, to no avail. Too tight and I start to hear a click from the bearings, so I've backed it off a bit.

The pulley does not look damaged in any way...it still looks quite new, in fact, and its only been used on and off over the last three years or so here. The pulleys seem tight, no play.

Wondering if anyone has any ideas here as to what might be causing the squeaking, and how to resolve it. Everything seems to work fine, I don't believe there is any power loss for any reason. Its more of an audible annoyance than anything else, but, I also want to make sure this isn't the beginning of something that will lead to other problems in the future as well.

FWIW, the weather is colder now. We get down into the 30s or low 40s at night, and during the day it may only reach 60. However I've never heard this squeaking before as far as I can recall, and I guess I turn more during the colder months than warmer.

Thanks!

 

[Steve Tiedman]

Hi Jon. Try popping the belt off the pulleys and run the motor. Still squeaking, it's a motor issue.

If it only squeaks when the belt is on and tensioned, maybe the pulleys are slightly out of alignment. A straight edge touching pulley faces can help determine that.

If all else fails, hardware and auto parts stores sell spray or stick belt dressing material that may knock down the squeaks.

 

[Jon Rista]

Hi Jon. Try popping the belt off the pulleys and run the motor. Still squeaking, it's a motor issue.

If it only squeaks when the belt is on and tensioned, maybe the pulleys are slightly out of alignment. A straight edge touching pulley faces can help determine that.

If all else fails, hardware and auto parts stores sell spray or stick belt dressing material that may knock down the squeaks.

Thanks Steve. Tested with the belt off, definitely the belt. As far as I can tell, the pulleys are as aligned as well I can see with my eyesight. I hadn't thought of automotive belt dressing, I'll give that a try.

It actually only seems to occur with the RPM is below about 1000rpm. Higher than that, and the squeaking stops. The slower the speed, the more pronounced, until the RPM is just a couple hundred RPM when it reaches its max. Hopefully the belt dressing will do the trick!