Skin effect happens at a high frequency. I forget what frequency but especially with a hub motor I remember it not being high enough to produce skin effect
14 awg is huge. Considering the size of these motors and assuming maybe n48 magnets if single strand and even wye terminated, which these don’t seem to be, I bet it would be maybe 19 awg to get a kv around 75-80. I was using a stator I think maybe twice as long and with thick steel behind each magnet, which was curved and much wider almost full fill and an air gap as low as .2-.4mm and would do 17awg and also wye to get 75kv. I did them almost all the same like that
U don’t find single strand winding or wye almost anywhere because machines don’t do it. Sometimes u can get more copper on with multi strand but almost always a single strand rewind will be not only more copper but the coils can be organized better so more inductance produced and easier to organize neatly leaving minimum gaps between coils which trap heat. Most inductance for least electrical resistance being the goal.
Winding thick wire isn’t hard and I now do 16 awg. U can’t put it on like in this pic above though and u need more leverage. I tie one end to a doorknob and pull it on. Very tight and when u figure what wire fits it just fits. If I didn’t do it just right it wouldn’t fit. Like a jigsaw puzzle.
I used “heavy build” wire. It has double the insulation. I’ve never heard thinner wire having less insulation just because thinner. The insulation is pretty fantastic as long as ur stator has not even the tiniest bit of bare steel otherwise it’s likely to scratch and short and big waste of time. U can really deform the wire no problem regardless of its size and msw wire told me for some of their wire they shape it after putting on the insulation.
Square wire would be ideal except insanely expensive in anything smaller than 16 awg and when so thin it ends up being too hard to stack it and ultimately it ended up worse for me every time I tried it. But if 15 awg or above it could be great. Not only because it’s more square and less voids between( it’s a bit round) but because u can stack. Otherwise with round ur forced to lay it on in layers along the tooth going bottom to top then back down and up again or it collapses.