Stepper hissing

Is a stepper making a hissing/sizzling noise after being run for an hour or so a bad sign?


I noticed it the other week after doing a longer run than normal of parts on the lathe, but all was quiet again the next time few times I used it. However I done another longer run this week and the noise returned. The motor is always cool to touch, so it's not like it's overheating.


It is an old round stepper, which I'm hoping will last another few months until I get a lathe replacement sorted, but should I be looking to change the motor soon?

Just a guess, but it could be something to do with the driver. Hissing=high frequencies present in the current, in addition to the usual chopping frequency (above audible range on any worthwhile driver) and stepping frequency. It maybe caused by the driver directly, or the motor causing the driver to have an effect on the motor. It's something that can be caused by poor design of the stepper driver, but clearly that's not the case here if it's run without the sound previously. Perhaps try the motor on a different driver? You could also verify that the holding torque of the motor is still close to rated, as that's quite easy to test. It could be some other machine/device interfering with the signals somewhere - I think I've had that happen before (although again seems unlikely as it's generally the motors that interfere with everything else, not the other way round).

I know there is an issue with the BOB (I'll never touch another CNC4PC product!) on the axis when the charge pump isn't running where it outputs spurious steps and the stepper ever so slowly creeps, but once the charge pump is active everything works how it should. The driver is a Gecko G251.

I'll just keep an eye on it for now and see if it gets any worse.

Steppers sometimes hiss and sometimes they don't - sometimes when they hiss a quick jab of the jog will stop them hissing - sometimes it doesn't. Like Jonathan has suggested - I've read that "poor" drivers can cause motor hiss - and yet I've had hiss from Geckos on and off - ('twould be a brave man I feel who claimed Geckos to be poor). I don't know really but unless you have other problems I'd just accept the hiss.

I've seen this "hissing" on baldor drives, and they're industrial quality. I doubt it's a problem to the motor, and not a sign of the motor failing.

I had terrible stepper hissing due to some cheap chinese TB6560 drivers....the steppers hissed because the driver board was totally sh1te (knocked together by some bloke partial to a bowl of rice & with only one criteria - cost).

I replaced the drivers in my same setup (for a USA driver) ...hissing gone