I have not yet installed the new axle, so don't know for certain, but it should be possible to cool (freeze) the axle, and warm the stator, and gain sufficient clearance to either just slip it right in, or gently tap it into place with a deadblow hammer and a wood block on the end of the axle, with a pipe (bigger ID than axle OD, but sized to fit against the stator's axle-core support so no stress is applied to any other part of the stator) between the stator and the surface you're pressing / hammering against.
If you have to use a gear puller, you're likely going to have to have the stator in the rotor with one side cover installed to have anything to pull against (spoke flanges), and use a spacer between stator (at the core around where the axle goes in) and side cover (to prevent squashing the windings), because you can't use the gear puller on the stator itself anywhere.
A press would let you setup a fixture under the stator so pressure is only applied at the core opposite to where the axle is going in, to prevent breaking or otherwise damaging the stator itself, windings, or support "spokes" between stator and axle-mounting core.
Removing the old axle is likely to require a press and a fixture as above, unless you can freeze the axle with CO2 or LN2, possibly while warming the stator support around it.
Before you try to remove the old axle, don't forget to remove the circlip securing it in place at the stator-axle support core.
Before you press in the new axle, don't forget to set the key into the keyway of the new axle, and align it correctly with the stator keyway.
An alternative that might be stronger for your application, depending on whether you use the freewheel mount, is to install a larger bearing on that side matching the one on the left side (may require using a left side cover as well, or modifying your existing right side cover), and using a "pipe axle" of that same large diameter all the way thru the stator and dropouts. You'd have to replace your dropouts with clamps that would secure it, but it would handle torque and impact better, with the much larger diameter, and makes passing the wires thru much easier, as well, as the entire axle is hollow.
See Farfle's custom dual-stator GoldenMotor Magic Pie thread for one way to do this.
https://endless-sphere.com/forums/viewtopic.php?f=30&t=34750&hilit=axle&start=225#p538389
xylene23nyc said:
I was wondering if anyone has successfully replaced a broken Axle on a Qs205 V3 Hub Motor?
Did you need a hydraulic press or was a certain sized gear puller sufficient? I have a replacement Axle on the way and could use any tips.
I am a recent victim of a nasty NYC pothole. Dual suspension won't save you here.