[ahecht]

This year, 190's Crab Goat was a rather simple design. We had our drill motors running into the FIRST 90 degree gear box, with our main wheels connected to the straight through shaft, and the crab wheels connected to the 90 degree shaft. I'll post a diagram of exactly how we accomplished that later.

The crab wheels themselves were raised and lowered by the Van Door motor using a simple linkage. We just used timing on the motor -- no limit switches.

The control was very simple. In regular operation, the crab wheels only drove straight, so the operator just pushed a button to drop them down, and moved one of the joysticks right or left to move the robot. We did have emergency kicker mode, which allowed us to drive with our crab wheels only (just in case something happened to our main wheels), but I'm not exactly sure how those were controlled.

I'll get you a diagram as soon as I can get a decent drawing program up on my PC.