Using RC Brushless motors as spindle

[M250cnc]

I took the steppers off the milling machine and put them on the router. Didn't want to put them back just for one part. Rotary table was also the most accurate way I could make the hole for the spindle, not having a boring head.

4 jaw chuck on the lathe ?

I measured the runout again now it's mounted properly. I put a 10mm cutter in and measured 0.03mm about 10mm from the collet. If I put the DTI on the collet chuck itself it reads 0.01mm.

Are you measuring the outside or the inside of the chuck for runout ?

You should be measuring the inside and i would measure at the extremes of the taper to see if you have different amounts of runout at the two points.

Phil