Turning down a servo motor shaft. Anything to look out for?

I’ve got new Chinese ac servos on the way as discussed in another post. The large 180mm frame y axis motor has a 35mm shaft and I’ll need to reduce it to 24mm to fit the pinion gear for the reduction gearbox, as per the original yaskawa.
Being an AC motor I’m assuming I can simply remove the rotor shaft assembly, chuck it up between centres and turn it down.
When removing the encoder can I just mark it’s location on the shaft and reinstall the same way? Will that be sufficient?

Basically what I’m asking is, what’s going to bite me on this?

I would strongly advise not to take the motor apart, you might end up with a paper weight.
It is an AC, but most probably a PM (permanent magnet) motor, so removing it from it's casing will badly mess up the magnetic field.
Clamp it to a lathe, wire it and let it run, use as a lathe spindle motor. No fuss, except clamping it down properly .

That’ll be fun
Will be interesting indicating it true with such a short shaft.

there are tupper returnings for shaft size reduction

is it a relal need or can you get the servo to a side and make some Timingbelt in between

taking the servo apart is always a risk of cracking the bearings

SPH wrote: That’ll be fun
Will be interesting indicating it true with such a short shaft.

Motor body ? Or is that tapered ?

The body is square but I don’t think I’d trust it to be perfectly true to the shaft. It’ll be fine, slowly slowly during setup and lots of checking with dial indicators will get it done.

I’m just glad you guys gave me the heads up on permanent magnet motors. That would have made for a bad day.