Build my own versions of Hero's automata

I was reading an old New Scientist which had an article called “Iropebot”. It explains how Hero, an ancient Greek engineer, created a simple cart which could be programmed to move forward, backward, pause, or go in circles. The instructions were encoded as loops around the axle of the cart.

It’s very clever and looks quite simple to reconstruct as long as I can get my hands on some conveniently-sized pieces of wood.