Blue Boy Version 1.0
I started with timing gears and belts but had issues with correct belt size, so I switched to chains and sprockets.. Realizing all the extra hardware required, I switched back to timing gears and found a way to splice timing belts.
Alas, there was so much "play" in the apparatus that I was sure would cause problems with control. At the same time I realized my Nema17 motors (one shown below) were too small for this big bot, so upgraded to Nema 23 and connected wheels DIRECTLY to the stepper motor shaft.