How to cut stepper motor shaft?

[harry11733]

Hi

I have to cut a hobbycnc 305oz-unipolar stepper motor shaft in order to fit it to a K2CNC z-axis. I know I could just add lots of washers but it would be a neater and stronger job if I just cut the motor shaft to the appropriate length. I am not sure how best to do this without damaging the motor and I am looking for suggestions.

[CarveOne]

Use a Dremel Moto-Tool fitted with one of the thin brown cut-off wheels. Heat sink the shaft between the place that is to be cut and the stepper motor end plate with a small vise grip plier clamped lightly on the shaft. Use high RPM and cut slowly so as to not overheat the shaft excessively. I have cut off the hardened stainless jaws of a digital caliper with relative ease, so the stepper motor shaft should not pose any problem for the cut-off wheel. Just try not to bind the wheel and break it, and use eye protection in case it happens.

CarveOne

[harry11733]

Thanks for the reply. I have an old milling machine and I was considering using that to clean up the end of the shaft after cutting but I don't really know whether the few end mills that I have could deal with the shaft metal. I got this mill for free and have not used it for any serious metal work and do not really know much about milling metal because I am mainly a woodworker.

[Andre' B]

If you can fix the Dremel Moto-Tool to the spindle on the old mill. Tape or hose clamp to a rod held in a collet etc.. You could put the stepper on the mill, shaft pointed up, connect up the stepper to its driver and get it spinning.
You could then do a very neat job of cutting the shaft off, even put a little chamfer on the end.

You may want to some kind of shield over the stepper around the shaft to keep the dust off it.