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 our 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 our magnetic encoder for micro metal gearmotors, to provide motor speed or position feedback.Gearmotor Dimensions
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.Motor Accessories
- Wheels and hubs: The micro metal gearmotor’s output shaft matches our assortment of Pololu wheels and the Solarbotics RW2 rubber wheel. You can also use our Pololu universal mounting hubs to mount custom wheels and mechanism to the micro metal gearmotor’s output shaft.
- Mounting brackets: Our mounting bracket (also available in white) and extended mounting bracket are specifically designed to securely mount the gearmotor while enclosing the exposed gears. We recommend the extended mounting bracket for wheels with recessed hubs, such as the Pololu wheel 42×19mm. Our micro metal gearmotors will also work with our 15.5D mm metal gearmotor bracket pair.
- Quadrature encoders: We offer several quadrature encoders that work with our micro metal gearmotors.
- Motor controllers and drivers: We have a number of motor controllers that make it easy to drive these micro metal gearmotors, including our qik 2s9v1 dual serial motor controller and our programmable Baby Orangutan and Orangutan SVP robot controllers. The qik 2s9v1 allows variable speed and direction control of two small, brushed DC motors using a simple serial interface; the Orangutans combine a programmable Atmel AVR microcontroller and dual motor driver all in a single package and make interfacing with the motor drivers simple when you use our Pololu AVR library. We also carry a number of basic motor drivers suitable for use with these motors, including the DRV8838 single-channel motor driver carrier, the DRV8833 dual motor driver carrier, the DRV8835 dual motor driver carrier, and the TB6612FNG dual motor driver carrier.
We also incorporate these motors into some of our products, including our 3pi robot and Zumo robot.Selecting the Right Gearmotor
We offer a wide selection of metal gearmotors that offer different combinations of speed and torque. Our metal gearmotor comparison table can help you find the motor that best meets your project’s requirements.