I am curious as to how he did that. I hope that it isn't causing extra friction somehow. We also use a drill motor to rotate a big telescoping arm, and we just use a cable tie ("premium" with metal tabs from Home Depot) to hold the shifter in low gear. Works great.

We have experienced what happens with low battery and I doubt that it would cause the breakers to pop. When the breakers pop, you get a clicking noise, and the robot shakes as the breakers go on and off. With low battery, you just stall when you draw a lot of current, and you get a yellow light on your operator control board.

As I said earlier, I would be looking for some smaller wheels. Good luck.

scuba_sm put a ring on some of the inside gearing. i don't know exactlyu what, but he was going to throw together a whitepaper sometime later.

Re: Argh!
 

The FIRST supplied drive train is a big improvement to the supplied parts this year. It should be used with good mechanical practices in order to perform.
1. There can be no binding in the shafts and the bearings have to be installed in a such a way that the bearings take all of the weight of the robot.
2. The bearing pairs have to be aligned so that they are on the same centerline and parallel to each other. The shaft passing through both bearing must be perpendicular to the face of the bearing.
3. The helical gears must be mounted at right angles to each other in order to minimize loading. If you can't turn the drive shafts by hand (easily by hand) then you can't expect the drill to be able to do it.
4. If you are tripping or drawing lot's of current climbing the ramp, you may need to switch to the lower gear ratio on the drill or use smaller wheels or both.
If you are not able to machine the drive train mounting holes accurately, then you have to use slots in the chassis to be able to move the components into alignment before tightening the mounting hardware. You may have to mount the bearings in movable plates as well, depending on your design. Don't despair because you have shipped already, you can accomplish these tasks as needed at regional events with simple tools. Ask for help, other teams are your resource. We will be glad to help anyone who needs assistance.