Just pulled another Ultramotor Hub apart using a large 3 arm automotive gear puller and decided to look at my old post to see if the instructions I wrote the 1st time were accurate. I noticed that I never mentioned that the hub halves are not keyed in any way so you should put a match mark across the seam to assist in lining them up for re-assembly.
And Yes, Tapping on the flange with a hammer or plastic mallet is crucial to the process. at first the puller should only be tightened up enough to apply some release pressure to the two halves. then lightly tap around the flange to relieve the pressure, making sure the gap is uniform before putting more turns on the puller. after tapping to relive the pressure, the puller should be fairly slack. tighten it up again and repeat the process. It doesn't really take very long but still, patience is the trick here. don't over crank the puller, just enough to tighten it. tap lightly around the opposite flange (i.e. the one that the puller isn't attached to) and it will come apart pretty easily.
for re-assembly respect the strength of those magnets. keep your fingers out of there when lining it all up. I used 2 large C clamps with some pieces of wood to protect the case. three clamps may have worked better but I only had 2 big enough for the job. And again, patience, work slowly, make sure it is going back together uniformly. tap on the halves with a mallet and/or move the clamps around if you have to to keep the gap even as you press it back together.
I have been running the last one I re-wired at 48V (16s Lifepo4) @ 45 amps and so far it has been working great. speed on a 26" rim is 30mph.
maybe another thing to note if you find yourself with one of these motors with a dead or questionable internal controller. both the dead ones I have dealt with had developed a major short. the 1st one I had blew while I was riding it and took out my BMS when it went. this last one I bought "untested" off of Ebay and was curious if it actually worked or not. curious but not entirely foolish. I wired up some old Sealed Lead Acid batteries I had with some thin gauge wires, attached them to the power leads and marveled momentarily at the flying sparks and smoke. so, I'm just offering a bit of warning against testing one of these with a battery pack that you like and perhaps also making a case for why you should have some SLA batteries laying around your workshop even if your E-bike friends make fun of you for having them.
DC