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Topic: Does a stepper motor get damaged if you turn it by hand? (Read 11784 times) previous topic - next topic

bestanamnetnogonsin

For my project it would be useful to test if the stepper is positioned properly by turning the axis of the motor by hand (while it is not connected to anything). Will this damage the engine?

raschemmel

No.  If you short the windings the motor will be harder
to turn due to the magnetic resistance.If you want it to
turn easily , leave the windings disconnected.

bestanamnetnogonsin

And theres no risk of damaging the motor? (because of internal mechanics or something)

keeper63

No - generally, you would have to turn it really fast to overspeed the bearings before it would be an issue; otherwise, no.

One real way you can damage a stepper motor is by taking it apart - never do this. It has something to do with the magnetic field in the motor being altered or weakened (or something) - it doesn't make it stop working, but it doesn't make the motor work better, either.

The only other thing I would consider (and this would have to be something you might want to measure) - is what kind of voltage/current comes from the stepper when it is being rotated by hand; the issue would be whether doing this could cause a great enough voltage spike to damage the drive circuitry. It isn't very likely (I would think the back-EMF during operation would be greater), but it might be something you would want to consider.
I will not respond to Arduino help PM's from random forum users; if you have such a question, start a new topic thread.

MarkT

The only risk in turning a permanent magnet motor is usually to the driver, since you could
over-voltage the driver if spinning the motor faster than its designed for.
[ I DO NOT respond to personal messages, I WILL delete them unread, use the forum please ]

KenF

Not at all.  In fact if you connect the coil windings to a pair of speakers (no power required) and then turn it by hand, you get some interesting sound effects.

westfw

If there is gearing involved between the motor and the part that you can manually turn, I believe you can damage the gearing.  This is supposedly a failure mode for hobby servo motors, because they tend to have "soft" gears near the output shaft


raschemmel

Quote
If there is gearing involved between the motor and the part that you can manually turn, I believe you can damage the gearing. 
This is an example of a geared stepper

This is an example of a non-geared stepper

bestanamnetnogonsin

Ive got the second one actually. So I guess turning won't be a problem.

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