Update! Download the small body if you are using these motors - https://www.sparkfun.com/products/8911 Have you ever wanted to understand what the P the I and the D terms of a PID controller actually do to a system? I know I have! Don't look to boring Hot plates and thermostats to learn. Learn from the PIDDYBOT. I have designed a robot, PCB, and program to use as a teaching platform. It uses PID control to make the robot balance. You can actively tune the system to see the effects on the robot. This is just the chassis, but a very integral part of the system! Go to http://www.idlehandsproject.com/?p=267 to see the rest of the components needed. Heres a video of the finished bot. http://www.youtube.com/watch?v=S9BQsCDw53s&feature=youtu.beGo to http://www.idlehandsproject.com/?p=267 to see the rest of the components needed.