robot

http://homepages.which.net/~paul.hil...ingTravel.html

If you can get some double pole double throw relays (aka double pole change over) and some microswitches that will do the trick.

Technobots and Maplin both do some that should be suitable.

technobots are cheaper i think

what is the overall size of the bot?

from blue wheel to blue wheel, the length (including and not including the lifter)

and finally the height from the ground to the top of the bot?

http://i1180.photobucket.com/albums/...R/88369b25.jpg
http://i1180.photobucket.com/albums/...R/a373260d.jpg
http://i1180.photobucket.com/albums/...R/825546f9.jpg
http://i1180.photobucket.com/albums/...R/7855f29e.jpg

width : (side to side) 470mm
length : (lifter to back) 520mm
length : (bulkhead to back) 350mm
height of chasis : 68mm
height of robot : 96mm