After some consideration with the Feigao 540Xl shafts and their taper from 5mm inside the motor to a 3mm outside the motor (also a chamfered taper) my students and I decided to try to press new shafts in place for the broken ones through the magnets. 5mm Oil hardened dowel rod .01 mm oversized was a perfect press fit. So if anyone has considered this and possibly thought it was impossible it is actually very simple. If details are needed I can supply them.