Miniature high-power motor from the Pololu MP series. Gear motor 250: 1, shaft speed is 90 rpm, torque is 3 kg * cm (0.3 Nm). The motor has an extended shaft which makes it easy to attach the encoder. Pololu 2384

30:1 Micro Metal Gearmotor HP with Extended Motor Shaft

30:1 Micro Metal Gearmotor

This gearmotor is a miniature high-power, 6 V brushed DC motor with long-life carbon brushes and a 29.86:1 metal gearbox. It has a cross section of 10 × 12 mm, and the D-shaped gearbox output shaft is 9 mm long and 3 mm in diameter.

A set of two magnetic encoders for use with Pololu DC Micro motors. The maximum resolution is 12 pulses per one revolution of the motor shaft. Powered from 2.7V to 18V. Pololu 4761

The sensors operate from 2.7 V to 18 V and provide digital outputs that can be connected directly to a microcontroller or other digital circuit. This module is compatible with all of the Pololu dual-shaft mini plastic gearmotors. Pololu 1523

250:1 Micro Metal Gearmotor

Unipolar/bipolar stepper motor. It has a resolution of 200 steps/revolution (1.8° per step), a nominal voltage of 5.7 V, and has a current consumption of 1 A per coil. Pololu 1476

This gearmotor is a miniature low-power, 6 V brushed DC motor with a 75.81:1 metal gearbox. It has a cross section of 10 × 12 mm, and the D-shaped gearbox output shaft is 9 mm long and 3 mm in diameter. This version also has a 4.5 × 1 mm extended motor shaft.

These 17 mm long aluminum adapters convert a 3 mm diameter shaft to a 12 mm hex shaft that compatible with many common hobby RC wheels. The set includes two adapters, two M4 screws for securing wheels to the adapters, four M3 set screws for securing the adapters to motor shafts, and one 1.5 mm Allen wrench for use with the set screws.

DC motor with hollow dome. Features a compact and lightweight design, making it ideal for applications requiring small size and low weight

Encoder for Pololu Wheel 42x19mm

Copper alloy traveling nut intended for use with Tr8×8(P2) threaded rods and features a mounting flange with four holes threaded for M3 screws. Pololu 2688

Bipolar stepper motor. It has a resolution of 200 steps/revolution (1.8° per step), a rated voltage of 3.5 V, and draws a current of 1 A per coil. Pololu 2298

Pololu high power miniature motor with carbon brushes. 210:1 gear motor, shaft speed 85 rpm, torque 2.5kg*cm. The motor has an extended shaft, which makes it easy to attach the encoder. Pololu 3054

KIT0014-B

A set of adapters (adapter) from the motor shaft 6 mm to 12 mm, wheel holders from RC models. Pololu 2687

Tamiya 72008 4-Speed Worm Gearbox Kit

Adapter that allows you to easily mount the wheels on a motor with a shaft diameter of 6 mm using screws size 4-40. The hub fits both round and D-shaped shafts. Pololu 1083

Pololu Universal Aluminum Mounting Hub for 1/4â€l Shaft, M3 Holes (2-Pack)