DIY Robotic Arm
 Easton LaChappelle (HalfFullEffects from Youtube) just took second place in the world in engineering at the Pittsburgh international science fair. I like the way he created his own servo motor, instead of just bolting a store bought servo into his project he used a DC motor which was connected to a potentiometer. The potentiometer was then used as feedback for determining the exact position of the motor. Watch the