Cooling
If you look closely at the stator, you can see that it has an airgap all around it, except for the connection to the shaft.
But even there, actually, it’s pretty much air-gapped.
This means that by default, the cooling of the coils will be very poor. I think in the original application there was not so much that could be done since the motors needed to be sealed against water and dirt ingression.
Drillin’ Holes
Let’s get one thing straight, stepped drill bits are awesome.
Yep, looks like some air will get to the stator.
I did a test-print, and it’s starting to look less like a hoverboard wheel and more like… I don’t know what, but not a hoverboard wheel. Looks cool though.
On the other side where there is no starfish, we can make big holes! Next time I would probably put them slightly further out. I doubt it makes a huge difference though.
Since the wheel should only spin a couple of turns, we could even add a fan here. This fan is just for illustration, it is completely the wrong size. Not sure how I would attach one, maybe just glue it?