50:1 Micro Metal Gearmotor





This gearmotor is a miniature (0.94" x 0.39" x 0.47"), high-quality, low-current motor with 50:1 metal gearbox, similar to Sanyo’s popular 12 mm gearmotors. These units have a 0.365"-long, 3 mm-diameter D-shaped output shaft.
Key specs at 6 V: 420 RPM and 40 mA free-run, 13 oz-in (0.9 kg-cm) and 0.7 A stall.


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 a custom-built encoder to provide motor speed or position feedback.

Gearmotor Dimensions

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). It 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.

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 the Pololu universal mounting hub to mount custom wheels and mechanism to the micro metal gearmotor’s output shaft.

Pololu wheel 32×7mm on a micro metal gearmotor.
Pololu wheel 42×19mm with micro metal gearmotor.
A pair of Pololu universal aluminum mounting hubs for 3 mm shaft.

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.

 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.

Black micro metal gearmotor mounting bracket pair with included screws and nuts.
White micro metal gearmotor mounting bracket pair with included screws and nuts.
Pololu micro metal gearmotor bracket extended with micro metal gearmotor.

 Quadrature Encoder: We offer a quadrature encoder for this motor that works with our extended bracket and 42×19mm wheel and provides feedback about wheel rotation (direction and speed). The encoder can be purchased as an individual unit or as part of an encoder set that includes two encoders, a pair of extended brackets, and a pair of 42×19mm wheels—just pick the particular micro metal gearmotor that best suits your application and you have a solution for closed-loop motor control.

Encoder for Pololu wheel 42×19mm with wheel, motor, and bracket.
Side view of the encoder for Pololu wheel 42×19mm, mounted to a bracket.
Oscilloscope capture of encoder outputs with the wheel spinning at 630 RPM.

 Motor Controllers: 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 inexpensive 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. All of the above controllers use the TB6612FNG dual motor driver, for which we also offer a simple carrier board.


50:1 Micro Metal Gearmotor MP Specifications


Size:     24 x 10 x 12 mm
Weight:     0.34 oz
Shaft diameter:     3 mm

General specifications

Gear ratio:     50:1
Free-run speed @ 6V:     420 rpm
Free-run current @ 6V:     40 mA
Stall current @ 6V:     700 mA
Stall torque @ 6V:     13 oz·in
Extended motor shaft?:     N