PU Wheel Friction Drive E-Bike

[Macaca]

This is a friction drive system I designed that uses PU wheel electric skateboard hub motor. Constant friction between motor and tire is maintained by two 1.2mm springs, and adjusted with zip ties on the other end of each spring. I'm using SONY VTC6 18650 6S2P batteries(22.2v 6000MAH), got a top speed of 15km/hr on flat ground. Planning on doing some more tests with higher voltage batteries.

STL files: https://www.thingiverse.com/thing:2556492

 

[fechter]

You might find it works better if you move the motor pivot further away from the wheel so the torque from the motor assists the wheel pressure.
Adding some kind of texture to the drive wheel will help, but not sure what would be best with polyurethane. Simply sanding it with super coarse sand paper might be better than nothing.