... It's pretty bad when you read the title of a post and think, "Hmm ... 'errrrCLICK....CLICKerrrrrrCLICK!!!'?? I bet it's a drill motor question!"
If the problem is electrical, my best advice would be give your system a rest once the breakers start to trip. Have some cold spray on hand, and spray a little on the fuse panel when you're letting your robot rest. Hopefully, the 40 amp fuses will be coming soon.
If your problem is mechanical, see the rest of the replies in this thread. We haven't done anything with or 1/2" drill motors yet, so from the mechanical aspect, I can't help you much. Sorry.
- Katie