How do stepper motors generally fail?

So I am wondering if it is bad to manually turn these stepper motors... and im wondering how do they break? Too much voltagE?

Most common way is grounded coils, either by to much heat damaging the enamel or mechanical grinding from wobbling axle due to worn bearings or too much pressure on the axle.

You can manually turn them as much as you want to, you will never cause any damage unless you are Bruce Banner........

Well, not to the motor, anyhow. Spinning a stepper *will* generate voltages and send them back upstream into the drivers (I have some gear where you can actually see the power supply LEDs iluminate if you do so). Thus, I recommend making any human driven stepper moves as slowly as possible, lest the back EMF damage something in the circuitry.

- Tim

@ tadawson

I can confirm this is true. Moving the heat plate fairly quickly causes two lights to turn on, while doing it more quickly nearly turns on 4...but i wont push it haha..