$1.500 in parts is not cheap but well worth the result if you ask me.
Trevor also built a self balancing 2 wheeled scooter, aka DIY Segway:
It is simpler to drive but not without its “problems“:
I get stopped every few blocks by someone ask about how it works. I don't mind telling people about it, but it does take an awfully long time to get to the coffee shop and back in the morning. And I can't quite drink a cup of coffee on it while moving at any speed, so the net result is that I arrive back at the office, 30 minutes later than if I'd just walked, with a cold coffee. A small sacrifice for Science
Cool Or What?
Via [Make vol 02, page 21]