Hi Guys,
I have been testing this home made friction drive to see if it could replace a hub for as an assist for commuting. Inspiration came from the friction drives here in the ES; I have put my own design changes to suit some goals. First, instead of using knurled roller and one way bearings, this one uses a live, smooth roller. The roller turns when the motor turns and no one way bearing.
The roller can auto-engage like some of the designs here, but I would rather manually engage or disengage as I don't use it all the time. Still like to pedal.
Each of the arm has a skateboard bearing to relieve stress on the motor bearings. So far, the roller/motor is holding after a few hundred miles.
Performance is acceptable--it feels like a 400 watt hub; first, it can accelerate from a dead stop without blowing anything, 22 mph/35 kph max. The motor is 53 mm/35 mm long, 235kv driving the 1.125" roller. Battery is 8AH 6S lipo and ESC is 80Amp max. This one is not stealthy as it is noisy at top speed. However, at 17-18 mph it is ok.
The design is symmetrical so it can accept 2 motors but I am pretty satisfied with the performance of one motor.
View attachment 2
I have been testing this home made friction drive to see if it could replace a hub for as an assist for commuting. Inspiration came from the friction drives here in the ES; I have put my own design changes to suit some goals. First, instead of using knurled roller and one way bearings, this one uses a live, smooth roller. The roller turns when the motor turns and no one way bearing.
The roller can auto-engage like some of the designs here, but I would rather manually engage or disengage as I don't use it all the time. Still like to pedal.
Each of the arm has a skateboard bearing to relieve stress on the motor bearings. So far, the roller/motor is holding after a few hundred miles.
Performance is acceptable--it feels like a 400 watt hub; first, it can accelerate from a dead stop without blowing anything, 22 mph/35 kph max. The motor is 53 mm/35 mm long, 235kv driving the 1.125" roller. Battery is 8AH 6S lipo and ESC is 80Amp max. This one is not stealthy as it is noisy at top speed. However, at 17-18 mph it is ok.
The design is symmetrical so it can accept 2 motors but I am pretty satisfied with the performance of one motor.
View attachment 2