[kawazuki]

Just had 3No. 23 frame steppers delivered and one seems a bit tighter than the other two - unpowered and rotated by hand. Its not outrageously tight just significantly more than the others. Do they 'wear in' with some use? I think i'll put it on my z axis which should get it loaded - thoughts anyone?:cheers:

[H500]

Make sure the wires are not shorted together. That would cause the stiffness.

[kawazuki]

Make sure the wires are not shorted together. That would cause the stiffness.

What? - just out of the box and not connected to anything?

[steve323]

What? - just out of the box and not connected to anything?

Yes, just wires touching each other adds a load to the motors. It closes the loop allowing current to flow through the coils and turns the stepper motor into a generator with a very low impedance load.

Try this experiment. Spin a stepper motor when all the wires are separated like spider legs. Then twist all the wires together and try to spin it again. The difference in torque required is amazing. It does not appear to harm the motors as long as you are just using finger force to turn the rotor.

Steve

[kawazuki]

Steve - top marks, gold star, go to the head of the class
I wouldn't have believed it but your right, I held all the bared ends together and couldn't turn the damn thing! Just waiting on the Gecko 540's to get released and i'll be away:banana:

[Fixittt]

but to answer the question, no steppers do not reqire a "BREAK IN" period like the old brushed motors do. Why... because they dont have brushes