Many readers of this blog have probably either built a mini-Sumobot or watched one in a mini-Sumobot competition. They are works of art, a tight little bundle of power, sensors and control, with one task in mind: push the other little bugger off the mat. The designs on these little bots vary widely in design as well as performance. Did I mention that they can be expensive? Even ready to make kits are over $100 shipped to your door. And if you are going to buy a lot of specialized parts online including the right motors, wheels, sensors and a brain can cost you a fair amount.