This gearmotor uses a motor with extra-strong magnets and a 75:1 metal gearbox to deliver a lot of power in a relatively small package. These units have a 0.315"-long, 4 mm-diameter D-shaped output shaft. This is the same motor used on the Dagu Wild Thumper 6WD all-terrain chassis 75:1. Key specs at 6 V: 130 RPM and 350 mA free-run, 120 oz-in (8.8 kg-cm) and 5.5 A stall.
These motors are intended for use at 6 V. In general, these kinds of motors can run at voltages above and below this nominal voltage, so they should comfortably operate in the 3 – 9 V range, though they can begin rotating at voltages as low as 1 V. Higher voltages could start negatively affecting the life of the motor.
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-, 80mm -diameter) or custom wheels and mechanisms to the gearmotor’s output shaft (see the left picture below).
We also stock Pololu's 25D Metal Gearmotor Bracket Pair that fits these motors.
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.
The face plate has two mounting holes threaded for M3 screws.
The diagram below shows the dimensions (in mm) of the 25D mm line of gearmotors. The value of 'L' is 23mm for this motor.