The Unofficial LEGO MINDSTORMS NXT Inventor’s Guide

I’ve put together some video of Guard-Bot, the robot from Chapter 15 of The Unofficial LEGO MINDSTORMS NXT Inventor’s Guide. As noted in the book, an interesting characteristic of this six-legged walking robot is that it uses two independent motors to power the legs, and each motor powers a set of three legs on its side. Normally, this would result in the robot’s legs eventually becoming unsynchronized (which would make walking very difficult–or humorous!). However, using the built-in rotation sensors in the NXT servo motors enables the robot’s legs to stay synchronized quite well.