[ZakuAce]

I was thinking about all this discussion of trailers. Would it be possible to turn the robot without involving the trailer? Like have the hitch on some sort of rotating...I'm not sure what the right word is, "cuff" comes to mind I don't know why...so the robot turns but the trailer stays stationary? Then the robot moves foreword and the trailer is pulled into position behind the robot.

Edit: Also I completely agree with the car steering drive train for a 4wd. It has the advantage of keeping your drive wheels in line with the direction you want to go. Even if you skid, your drive wheels should be able to pull you back on track, like a car on ice. A skid drive means all the wheels face the same direction, giving you less control.

Edit 2: I wouldn't worry so much about having to back up, this is a small problem compared to getting your entire robot to maneuver correctly.