Currently I had some work on recycled wheelchair hubs.
I want to build one side mounted, driven rear hubs with drum brakes.
Normally these hubs are spinning around a fixed 12mm axle.
After removing the axle and hammering out the bearings, i put the hubs on the turning lathe, widening the center hole of the drum hubs to nearly 25mm.
Then I pressed the new 25x2 cromo steel axle into the hub.
Additionally, i welded a flange to the outer end of the axle tube, screwed to the hub to make sure a proper torque transmission.
Left: Front hub with usual 12mm axle
Right: same hub after being converted into a driven rear hub
with 25mm axle and outer torque flange.