Not good for a stepper motor?

[FLUTE HEAD]

I have a bipolar stepper motor. Sometimes I shut off the power to my power supply in order to do some manual machining. The only problem is there still seems to be, what I believe, is electricity in the stepper motor and this causes cogging and resistance if I try to turn the stepper by hand at any fast or even descent speed. I guess this is what is meant by powering down the stepper. Anyway, does forcing the motor to turn with cogging and resistance hurt a stepper motor in any way? How can I power down the motor before turning manualy?

[RotarySMP]

You are using the stepper as a generator. This won't hurt the motor at all. It could potentially hurt your drive if you turn the motor really fast and have way of dumping the back EMF back to the PSU.

You would have to disconnect at least one lead wire per phase. The motor would still exhibit some cogging though.

[swarfmacdaddy]

What type of drives are you using? I have Gecko g201s and didnt have the funds to finish my cnc for awhile, and kept the motors hooked up to the drives while cranking on the handwheels real fast and ended up blowing the opto to one of them. Now i have the disable hooked up like i should have. Its also takes alot less effort to do manual turns. Especially with 580 ounce inch motors.

[FLUTE HEAD]

"Now i have the disable hooked up like i should have"

Randy, I'm using the xylotex 3 axis board. Could you or someone guide me onto how I can hook-up a disable. From what I gather, I guess I need to "drain" the electricity from my motors so they will be easy to turn. Is there a quick and easy solution? thanks

[swarfmacdaddy]

Flute, Sorry to take so long to get back to you but i havent checked me email for a while. If you go to the Xylotex website look for the pdf file entitled preliminary 3 axis datasheet, and on page 6 of 8 under the heading of ENA# inputs it gives pretty clear instructions on how to hook up the disable function. It also gives alot of warnings about back EMF voltage to the drives. Hoped this helped.