Quantity   Component name
1 × Lego 70808 Super Cycle Chase Believe it or not, all of the Lego parts came from this one set—except for an 8-tooth gear.
1 × Small stepper motor I honestly have no memory of where I got it. It's not much bigger than a toy DC motor and is unipolar so it's not super strong, but it was pretty easy to cook up a driver circuit for it.
1 × SG-5010 servo motor It's a standard large servo
6 × 2N3904 NPN transistor
4 × 1N4148 signal diode Electronic Components / Misc. Electronic Components
6 × 1 K resistor
1 × Arduino Leonardo We're CURRENTLY using an Arduino because we were in a hurry, but we're going to try a few different controllers besides that.
1 × 10 K potentiometer Only temporary for manual control