I’m a sucker for interesting robots. Especially if they are built out of Legos. Everybody loves the Legway, but you have to admit that the concept is overly simplistic. The real challenge is building the system around the limited resources of Lego’s RCX.

Now meet another balancing robot courtesy of Maurits Kooiman on Lugnet. This one balances on one wheel and apparently uses two RCX bricks and four sensors along with three tires to maintain balance on the axis perpendicular to its unicycle. The robot balances on the main axis by directly powering the wheel. The axis perpendicular to its unicycle is balanced by the set of rotating tires. The fourth tire seems to be a freely swingy pendulum, but it may in fact be controlled by yet another motor. Check out the video!