Hello everyone, I am designing a 4WD differential robot that has to fit inside a 7" cube, and I am having trouble finding a DC motor with an encoder that is small enough to fit inside my robot. This is my conceptual chassis design, using 2" wheels from AndyMark, and the wheels are only 3.8 " apart so I am imagining that probably a wormgear motor is the best solution (since I can build upwards). Does anyone know of any good suppliers that make such small motors? The inner diameter of wheels is 8 mm but I will mostly make a conversion plate anyways so the shaft diameter of the motor is not important.

Thanks!