Sparky - DIY Web-Based Telepresence Robot

Step 9 CHASSIS & DRIVE TRAIN - 2

The VEX kit includes many great parts, including standard servos with a limited 180* range of motion, but also two full-rotation motors  servos which spin completely around like DC motors. These are convenient because they simplify the requirements to create full-rotation wheel motion. (The original Sparky robot had 2 limited range servos, but these didn't drive the robot wheels directly. Instead they physically moved potentiometers that were connected to the original wheelchair controls  a seemingly complex Rube Goldberg-like solution that has worked surprisingly well for years but still makes most engineers nervous!).