This compact, inexpensive plastic gearmotor (brushed DC motor with a
120:1 reduction gearbox) is well suited for use in small robots. While
intended for operation at 4.5 V, it should run comfortably in the 3 V to
6 V range. The gearbox has a 9.7mm-long, 3 mm-diameter D-shaped output
shaft that is perpendicular to the motor shaft, and a built-in safety
clutch helps protect the gears from excessive loads. This version also
has a 5x 1.5 mm extended motor shaft.
Key specs at 4.5 V: 120 RPM and 80 mA free-run, 20 oz-in (1.4 kg-cm) and 0.8 A stall.
These brushed DC gearmotors are compact and affordable — perfect for building a quick, miniature robot. They are intended for use at 4.5 V, though in general, these kinds of motors can run at voltages above and below this nominal voltage, so they should operate comfortably in the 3 V to 6 V range (rotation can start at voltages as low as 0.5 V). Lower voltages might not be practical, and higher voltages could start negatively affecting the life of the motor. The plastic gearbox is protected by a built-in safety clutch that will typically slip before the gear teeth can shear (typically when the load exceeds around 25 oz-in, or 2 kg-cm).
The mini plastic gearmotor family offers two output shaft orientations relative to the motor shaft (offset and 90), two motor options (normal and high-power, or HP for short), and two gearbox options (120:1 and 180:1). The 120:1 versions are white and the 180:1 versions are yellow:
Some versions of these gearmotors are also available with an additional 1.5 mm-diameter output shaft that protrudes from the rear of the motor. This 5 mm-long rear shaft rotates at the same speed as the input to the gearbox and offers a way to add an encoder, such as our magnetic encoder for mini plastic gearmotors, to provide motor speed or position feedback:
Please see the mini plastic gearmotor comparison table for detailed specifications of all our mini plastic gearmotors. This dynamically-sortable table can help you find the gearmotor that offers the best blend of speed, torque, and current-draw for your particular application.
This item has a low-power motor (800 mA stall current), a 120:1 gearbox,
and a 3 mm diameter “D”-shaped output shaft that is offset from but
parallel to the motor shaft. The 1.5 mm diameter motor shaft extends
approximately 5 mm past the base of the motor. See the dimension diagram (69k pdf) of this gearmotor for more information.