Powermatic 3520 - high pitch noise

[Strokes77]

New to me 1999 Powermatic 3520.

Runs well, seems to have full speed range, reverse, and enough torque.

But, when it is on it's slowest speed, there is a high pitch electrical sounding whine.  It continues as speed increases, changes pitch, but still there.

Is this an issue? Other than annoyance?  Or normal?

I am selling old lathe and setting this one up as my primary, want to make sure it's good to go before committing.

[MidwestMan]

I have a 3520A (which looks the same as yours) and I have no such issue AT ALL. All nice and quiet here. I don't know what is causing your noise/squeal.

[Strokes77]

It's more of an electrical type hum. It does it even when spindel not turning. Just when speed is turned on a tiny bit.

[Wipedout]

Mine doesn't do that so it would concern me

[stoppy]

Mine is a "3520B" and has never done that.  It would concern me.

[Strokes77]

Here's a link to a video.

Any ideas?

https://youtu.be/4zi-58pIl-4

[MidwestMan]

I suspect an electronic component, like transistor, that is the culprit. May or may not be risky to use, but is annoying. (Fire risk, I meant)

[MidwestMan]

I'd call powermatic customer service and see if they'd work a repair/swap or something like that. If you're a dyi guy, I suppose you could try to locate the component and replace it yourself.

[Joe K1]

My high frequency hearing is gone.  What I hear sounded like bearing noise.  Remove the belt from the motor pulley and operate to determine if there is spindle bearing noise.

[Souperchicken]

Hard to tell for sure but I think it's normal, I have the same lathe (mines a 2005) and it also whines, especially noticable at very slow speed. I think it's just the inverter drive electronics switching noise, maybe there's an inductor that whines or possibly the motor windings themselves. I wouldn't worry about it.