machining a stepper motor

[greywolf]

I'm doing a special setup with a g251 and a nema 17 stepper.

I want to pull the endcaps off the stepper for machining on my mill.

Can I get away with this without harming the stepper?

I do not plan to remove the rotor as I know this would instantly trash the motor, though I don't know why this is so. But I'm wondering if the rotor might shift out of place with the endcaps off and whether or not even a tiny shift will kill the motor.

[Mariss Freimanis]

You can do that if:
1) You do not remove the rotor from the stator.
2) You dissasemble / reassemble the motor in a very clean area free of any steel particles.

Mariss

[neilw20]

Making sure you go no magnetic contamination is the most important.

On the outside of the motor there will be inevitably be some whiskers, even so fine you can't readily see them.

Use opaque adhesive tape to remove all the whiskers and and any other fine bits of magnetic detritus.
The opaque tape is good. Just keep applying it and pulling off until is stays perfectly clean.
When it is apart don't remove the rotor, and try not to rotate it as while it is poling it will scrape and start to make whiskers/dust. Just waste plenty of sticky tape.
Once disassembled store in a resealable plastic bag. Now the bag can get contamination on the outside, so keeping the first bag perfectly clean, store the whole lot in a second bag. Then put it well removed from ferrous contaminants especially the bench grinder.
Kitchen tables might be safe, but does the wife use steel wool?
Consider the storage/assembly environment before you start and ensure you have uncontaminated bags and adhesive tape ready.

[greywolf]

Thank you both, Mariss and neilw20, for your helpful advice.