The Building Of Theta.

This is an accounting of my (attempts) at building a functional scale mobile AI. By functional scale I mean to indicate a frame of sufficient size to have true interaction and impact with its surroundings. I use the term “mobile AI” in that the word Robot has mostly been overrun with radio controlled toys, overly simplified mobile intelligent controllers that follow a line on the floor or telepresence devices with no real “Brains On Board”. My interests have grown to a level that requires the next logical step.

Drawing on the brilliant work from Willow Garage, I plan to employ the use of their open source ROS (Robot Operating System) on top of Arch Linux.

I wanted to build a steel frame for my mobile AI that would use wheel chair motors on the front for simple differential steering and a swiveled coaster wheel in back. I wanted good ground clearance so the device could travel on unpaved areas. The strong steel frame to support the large motors and heavy lead acid deep charge batteries was a must, and this meant I would need to learn how to weld.

I signed up for a welding class from from a local “hacker space” called Hazard Factory. I would highly recommend that anyone planning on doing any form of welding to take a class. My instructor was quite knowledgeable on all aspects of welding and fabrication and covered everything from safety to the types of metals to weld, to the types of welding like stick, MIG, and TIG, then we moved onto hands on welding. I found this to be an invaluable experience in that in what I call “my young and stupid days” I had been blasted a few times with high voltage (once from the fly-back transformer of an old 25” color console TV at well over 1500 volts) and this had given me an unnatural terror of high voltages, but seeing how at ease our instructor was at welding small strips of metal with almost no effort at all, the crackling of the MIG welders became tolerable and now are quite a welcome sound. I still have a healthy respect for high voltage, but am now comfortable with welding.

After taking the welding class I was looking around for a good little MIG welder and came upon the MIG 135 Welder, cart & Helmet Kit from Eastwood. I have been using it for a few months now and am quite pleased with the results. I don't have 220VAC in my garage, and getting it put in would be quite a lot of $$$$, so this little 110VAC welder was the best option for me. I had a little 110VAC stick welder that was totally useless now sits on the floor in a corner till I can get rid of it.

Some of the photos now listed are of early construction of the chassis: