Originally Posted by
Phantoj
How about gear reduction between the motor and the larger diameter shaft?
But I think even with a very large roller, you will have a roller slippage problem.
I think the fake gearshift idea is a bad one.
1. Gears are noisy, expensive and reduce the efficiency. If I went this route I'd probably use belt drive systems for motor RPM reduction. It is silent and cheap.
2. I am going to talk to an engineer but the basics here I think that increasing roller diameter will increase contact area. And if normalized pressure between roller and tire kept the same then the friction should grow as a square of shaft diameter. So if we triple roller diameter (easy) then we should get 9 times more friction between tire and the roller.
3. May be it is may be it is not. That is what I am trying to figure out.