JK - Pololu - 2377

This gearmotor is a miniature high-power, 12 V brushed DC motor with long-life carbon brushes and a 100.37:1 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.

Key specs at 12 V: 320 RPM and 100 mA with no load, 30 oz-in (2.2 kg-cm) and 0.8 A at stall.

A small, powerful motor with 210: 1 metal gear, 12 V operating voltage, power consumption from 0.06 A to 0.75 A, 160 RPM, maximum torque of 2.5 kg * cm and carbon brushes with increased durability. Pololu 3043

Small, high power motor with 380: 1 metal gear, 6 V operating voltage, 0.1 A to 1.5 A power consumption, 85 RPM, maximum torque of 5 kg * cm, carbon brushes and double-sided shaft. Pololu 4797

10:1 Micro Metal Gearmotor HP

210:1 Micro Metal Gearmotor

10:1 Micro Metal Gearmotor HP with Extended Motor Shaft

This gearmotor is a miniature high-power, 6 V brushed DC motor with long-life carbon brushes and a 150.58:1 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.

50:1 Micro Metal Gearmotor with Extended Motor Shaft

Miniature high-power motor from the Pololu MP series. Gear motor 5: 1,
the rotational speed of the shaft is 4400 rpm, the torque is 0.1 kg * cm (0.01 Nm).
The motor has an extended shaft which makes it easy to attach the encoder. Pololu 2376

75:1 Micro Metal Gearmotor MP

100:1 Micro Metal Gearmotor with Extended Motor Shaft