These tiny brushed DC gearmotors are intended for use at 6 V, though 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 (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 micro metal gearmotors are available in a wide range of gear ratios—from 5:1 up to 1000:1—and offer a choice between three different motors: high-power (HP), medium-power (MP), and standard. With the exception of the 1000:1 gear ratio versions, all of the micro metal gearmotors have the same physical dimensions, so one version can be easily swapped for another if your design requirements change. Please see the micro metal gearmotor comparison table for detailed specifications of all Pololu's micro metal 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. A more basic comparison table is available below.
Some versions of the gearmotors are sold with an additional 1mm-diameter output shaft that protrudes from the rear of the motor. This 4.5mm-long rear shaft rotates at the same speed as the input to the gearbox and offers a way to add an encoder, such as Pololu's magnetic encoder for micro metal gearmotors, to provide motor speed or position feedback.
Note: The 1000:1 gearmotors can generate enough torque to damage themselves. The stall torque values given for those two motors are theoretical, and Pololu strongly recommend you avoid stalling them.
Details for item #999
Exact gear ratio: (35×37) / (13×10) ~~ bb(9.96:1)
|Micro metal gearmotor dimensions (units in mm).|
The gearbox has a long (0.365" or 9.27 mm), 3 mm-diameter D-shaped metal output shaft, and the brass faceplate has two mounting holes threaded for M1.6 screws (1.6 mm diameter, 0.35 mm thread pitch). The gearmotor weighs approximately 0.35 oz (10 g). Versions with the extended motor shaft have a 1mm diameter round shaft that protrudes 4.5 mm from the rear of the motor, between the two motor terminals; this is not pictured in the above dimension diagram. In terms of size, these gearmotors are very similar to Sanyo’s popular 12 mm NA4S DC gearmotors, and gearmotors with this form factor are often referred to as N20 motors.
The gearbox on the 1000:1 and 1000:1 HP micro metal gearmotors is 12.5 mm long. All of the other micro metal gearmotors have 9mm-long gearboxes, as shown in the above dimension diagram.
|Black Pololu 70×8mm wheel on a Pololu micro metal gearmotor.|| |
|Black Pololu 90×10mm wheel on a Pololu micro metal gearmotor.|| |
|Pololu 30T track set with drive sprocket mounted on a micro metal gearmotor to the left; idler sprocket is on the right.|
- Quadrature encoders: Pololu offer several quadrature encoders that work with Pololu's micro metal gearmotors.
Pololu also incorporate these motors into some of Pololu's products, including Pololu's 3pi robot and Zumo robot:
|Pololu 3pi robot.|| |
|Assembled Zumo robot with a Zumo Shield, Arduino Uno, and Zumo blade.|
Selecting the Right Gearmotor
Pololu offer a wide selection of metal gearmotors that offer different combinations of speed and torque. Pololu's metal gearmotor comparison table can help you find the motor that best meets your project’s requirements.
|Some of the Pololu metal gearmotors.|