I built this steam bent Oak caterpillar in 2002. It has wire-wrap IC circuit that counts motor revolutions and turns on and off motors in a specific sequence to make the caterpillar walk. The next caterpillar I made used a cam and cables, and that led the way to making my overhead wave sculptures. But this one got put into a crate and set aside for 20 years. Last year I took it out of the crate and luckily there was a note about how to turn it on. I followed the instructions and got it running again!