378:1 Metal Gearmotor 25Dx58L mm


This cylindrical, 2.28" x 0.98" x 0.98" brushed DC gearmotor with a 378:1 metal gearbox is a lower-current , lower-speed alternative to our 25D mm HP gearmotors. These units have a 0.315"-long, 4 mm-diameter D-shaped output shaft.

Key specs at 6 V: 15 RPM and 80 mA free-run, 250 oz-in (18.0 kg-cm) and 2.2 A stall. (Note: stall torque and current specifications are theoretical values; stalling the motor is likely to damage the gearbox.)

Gearmotor Dimensions

These gearmotors have output shafts with a diameter of 4 mm. The Pololu universal aluminum mounting hub for 4mm shafts can be used to mount our larger Pololu wheels (60mm-, 70mm-, 80mm-, and 90mm-diameter) or custom wheels and mechanisms to the gearmotor’s output shaft (see the left picture below). These are the same type of motors used in the Wild Thumper all-terrain chassis, and the gearbox’s output shaft works directly with the 120mm-diameter Wild Thumper wheels.

Pololu 60×8mm wheel on a Pololu 25D mm metal gearmotor.
Dagu Wild Thumper wheel 120×60mm (chrome) with Pololu 25D mm metal gearmotor.

The face plate has two mounting holes threaded for M3 screws. You can use our custom-designed 25D mm metal gearmotor bracket (shown in the picture below) to mount the gearmotor to your project via these mounting holes and the screws that come with the bracket.

Pololu 25D mm gearmotor with bracket.

The diagram below shows the dimensions (in mm) of the 25D mm line of gearmotors. The value of L is shown in the table below.

Dimension diagram (in mm) for the 25D mm metal gearmotors.


Size: 25D x 58L mm
Weight: 3.4 oz
Shaft diameter: 4 mm

General specifications

Gear ratio: 378:1
Free-run speed @ 6V: 15 rpm
Free-run current @ 6V: 80 mA
Stall current @ 6V: 2200 mA1
Stall torque @ 6V: 250 oz·in1



This is a theoretical value; stalling the gearbox output shaft is likely to damage the gearbox.