Free Spinning a Stepper Motor

[Hellbringer]

hi,
i am thinking about making the hoss tapping attachment but i dont want to have to change belts back and forth is it possiable to free spin a stepper motor at the speed of the spindel (up to 2500 RPM) or will it destroy the stepper?

thanks mike

[SpeedsCustom]

I would not suggest it at all. Not a good idea. that my 2 cents though. I feel there would be way too much friction.



-Jason

[BrendaEM]

It may be worse than that. Spinning the stepper fast might generate enough power to destroy the drivers, and perhaps the motor. perhaps you could devise some kind of clutch, or use one from an auto air conditioner compressor. Zeroing it might be an issue.

[Hellbringer]

yeah the clutch was option 2 just free running stepper would be easier

thanks guys for the input
Mike

[BrendaEM]

[Also, the drive pulleys multiply the spindle speed, it probably would be well over the rated RPM of the stepper motor, otherwise you could disconnect the electrical, leaving it a mechanical issue. Unfortunately, the multiplied speed would be much faster than the spindle, fast enough probably to smoke the bearings, throw and magnets.]

You might be able to make an over-top-center cam type arrangement, such as vice-grips locking pliers, and fixture hold-downs, and Kraig's fixtures use. You could flip a lever, releasing a idler pulley, and slide the belt off. I you use the system, I would even wrap the lever closed with velcro, just to make sure it couldn't pop open, causing the drive system to lose its indexing place.

[SpeedsCustom]

Also, Stepper motors have a lot of resistance, even under-power. So spinning it with the actual spindle as well would cause resistance back into the belt and motor. It would be like having a brake on your belt and you would be smoking it.


-Speed