Didel Module 0.3 Gears - 9-tooth pinion, 0.81mm bore, for 6mm and several 7 mm pagers. Measures 4.47 x 3.14 x 3.14mm.
Didel Module 0.3 Gears - 12-tooth pinion, 0.78mm bore, measures 3.50 x 4.00 x 4.00mm.
12 tooth pinion, 0.82mm bore for 6mm pagers. Measures 3.46 x 3.96 x 3.96mm.
This silicon tire makes a great replacement for your worn RW2-series tires.
HXT900, one of the most famous and the best value micro servos available. We have them here at Solarbotics!
A 3A, 8-45V bipolar stepper motor driver - this breakout packs a mean punch for it's size! It has built-in overcurrent detection, undervoltage detection, overtemperature detection, stall detection, a 5-bit ADC, and a switch input, microstepping support and PWM drive voltage limiting.
You got some really big motors you want to control? Take a look at the Sabertooth dual 25A motor driver, able to supply 25A each to two motors, at up to 30V. It's a brute, but it's smart enough to talk in many ways!
The Sabertooth 2x5 motor driver is a compact, flexible way to drive motors up to 5A. It talks in 4 methods, so you're sure to be able to use it for your project.
The HB-25 Motor Controller in a fast and inexpensive way to control a DC motor up to 25 Amps.
Just need to make some motors move with your Arduino? Here's a simple way from SparkFun - the Ardumoto!