My other hobbies seem to be involving more and more tube electronics, so I thought it would be fun to build yet another combat robot, this time controlled by a vacuum tube circuit. Tubot is in the early stages of development right now - no electronics, just a chassis epoxied together with the bare main board mounted. I'm currently studying the circuits of W. Grey Walter's tortise robots, which were built to experiment with electronic models of neurons back in the late 1940s and early 1950s. Pictures below, showing Tubot with its load of batteries - 12 volts worth of AA batteries and a 45 volt B battery - along with one of the tubes that may or may not populate that board, depending on how things go. Sensors are tentatively planned to be 3 pairs of cadmium sulfate photo cells and ordinary flashlight bulbs. Power is a pair of Lego gearhead motors permanently epoxied to the chassis and reduction geared by an additional 20:1 to lego wheels. This setup proved competative in the first iteration of Lego Avenger, and hopefully will do the same here. More on this project as it progresses. Oh, and the top shell will probably be replaced with lexan so people can *see* that the silly thing is tube controlled. One of my goals is to build a machine that (save for the chassis itself) could have been built in Walter's day. So far the only component that violates that are the photocells, which I chose because they're cheaper and easier to find than their selenium counterparts. Note the 45 volt B battery (it looks like a 9 volt battery on steroids) currently at the rear of the roof of the bot.