MarkT:
I hope they are not plexiglass walls, they shatter.You mean polycarbonate??
Anyway the problem with magnets is you need nice flat areas of contact for large forces, and wheel surfaces are
not planar.Magnetic tank-tracks?
If you had magnetic tank tracks you still run into the problem where the ones in contact with the ground shouldnt be on or else the track wouldnt move. you need the links that are on either side that are hovering above the ground to be turned on to move the track and create motion.
THat is a good point that you need flat areas. Do you think it would help if I had smaller coils that were tightly packed together that way the ones I want to turn on would be closer to the flat surface of the steel?