Direct drive minibot - output diameter?

[boomergeek]

Originally Posted by Ether

Could you provide a bit more detail? What exactly didn't work?

Our 4 lb robot just destroyed both latex tubing and shrink tubing for small diameter shafts and 4 lbs would stall for larger diameter shafts that gave enough surface area under enough normal force. It is possible that someone can find a surgical tubing that can hold the pole with the very little surface area of smaller diameter shafts without getting destroyed.
(But energy is better spent on lightening the minibot to allow a larger diameter shaft).

The related issue is the normal force on the wheel needs to be proportional to the weight of the minibot. There was another thread that did some experiments to determine optimum normal force.

So in effect. the stress on the tread was geometrically reduced by the reduction of the weight of the robot.