inrunners or outrunners

[Rapidrory]

I'm looking at using heavy duty timing belts instead of spur gears for brushless drive, as the weight of the gears detracts from the weight saving of having lighter motors. If I can get my mill to make some UHMWPE pulleys for it then even better (I'm not sure if 3D printing would quite cut it at that scale). Ideally I'd need to find a suitably low KV high power brushless that can use relatively low ratios to help stop the belts stripping on the smaller pulley. I've found a perfect setup for feathers (1.5kw 190kv motor on 6s, 4:1 to the wheels) but haven't really looked into heavy setups for this just yet.

Just as a note, VESCs don't really like high pole count and/or high KV motors too much; anything above about 80K ERPM max and they become a bit unstable. (ERPM is the RPM x the number of motor poles / 2)

By the sounds of it Ellis you might need to look into designing a 'Jupiter' gearbox soon!