Remix of Dual Mode Spring Motor Rolling Chassis

I really liked this design that Greg Zumwalt made. I started off just redesigning the rear wheels so I could use the #222 O-Rings from http://www.harborfreight.com/382-piece-o-ring-assortment-67554.html since this o-ring set did not have the #223 size. Initially I thought the wheels might be too complex for me to modify, but they turned out to lend themselves well to modifying. After printing a couple of the smaller gears, my printer had problems printing to these tight tolerances. I decided t