Hexapod walker (RCX)

This small LEGO MINDSTORMS RCX hexapod robot can walk and turn in place. It has three motors:

• Two motors move external legs forward and backward.
• A central motor raise the robot at left and at right, driving the middle legs.

The robot is built with a Mindstorms RIS 1.5 kit.

The motors drive external legs with a gear train with ratio 1:15. To reset them to the center position, I use two touch sensors pressed by cams. The middle motor has a gear ratio of 1:5 and uses no sensors: the center position is reached automatically by setting the motor in floating mode. To remote control it, I developed only a simple routine that responds to IR remote, using message 2 to go/stop/reverse and messages 1 and 3 to turn in place.