Pololu 1520 - 120:1 Mini Plastic Gearmotor HP 4.5V, Offset 3mm D-Shaft Output, Extended Motor Shaft

Overview:

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).

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:

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. A more basic comparison table is available below:

Motor Type	Stall Current @ 4.5 V	No-Load Speed @ 4.5 V	Stall Torque @ 4.5 V	90° output	90° output + motor shaft	offset output	offset output + motor shaft
high-power (HP)	1250 mA	150 RPM	25 oz-in	120:1 mini HP	120:1 mini HP	120:1 mini HP	120:1 mini HP
low-power	800 mA	120 RPM	20 oz-in	120:1 mini	120:1 mini	120:1 mini	120:1 mini
		80 RPM	30 oz-in	180:1 mini		180:1 mini

Note: The stall torque values listed are approximate, and the built-in safety clutch might start slipping at lower torques.

The gearmotors in the table above all have a 3 mm diameter D-shaft output. These shafts are just like the ones on our micro metal gearmotors and are compatible with many Pololu wheels and our 3 mm universal mounting hubs. We also carry two low-power, 120:1 mini plastic gearmotors with 2 mm diameter spline outputs: 90° 2mm spline output and offset 2mm spline output. These gearmotors all work with our wide and tall mounting brackets for mini plastic gearmotors.

Details for item #1520:

This item has a high-power motor (1250 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.

Dimensions:

General specifications:

Notes:

1 See drawing for detailed dimensions.

2 D shaft.

3 Note: the gearbox's built-in clutch might start slipping at a lower torque.