This 143:1 gearmotor (gearbox with brushed DC motor) is a faster version of the GM3 gearmotor. It is a great low-cost alternative to modified hobby servos or Tamiya gearboxes. The low-current motor is a perfect match for our qik 2s9v1 dual serial motor controller, and the compact size makes this unit an attractive choice for small robot designs.

This gearmotor comes pre-assembled, with the gears fully enclosed. There are built-in mounting holes, and the output shaft is 7 mm in diameter with two sides flattened. Please note that the output shaft is slightly shorter than on the GM2 and GM3 gearmotors. This motor also comes with a built-in safety clutch.

Compatible products include a custom-molded GMPW plastic wheel, and the Solarbotics GMW motor mount, which can be used as a wheel itself or as a mounting point for other wheels or mechanisms. Solarbotics makes a mounting bracket that works with this motor, and our L-brackets and extended L-brackets for plastic gearmotors are also compatible with this motor (though you might need longer screws than the ones included with the Pololu brackets).

For similar gearmotors, you might want to take a look at:

To increase the power of this gearbox, you can replace the motor with a higher-power RM2 motor. For a replacement motor, see the RM3 motor.


  • Description: 90-degree
  • Gear ratio: 143:1
  • 3 V Operation:
    • No-load RPM: ~ 40
    • No-load current: ~ 50 mA
    • Stall current: ~ 400 mA
    • Stall torque: ~ 44 oz-in
  • 6 V Operation:
    • No-load RPM: ~ 78
    • No-load current: ~ 52 mA
    • Stall current: ~ 700 mA
    • Stall torque: ~ 76 oz-in
  • Weight: 33 g

Solarbotics GM9 gearmotor dimensions (in mm).

You can download a pdf version of this drawing with imperial dimensions (100k pdf) or metric dimensions (100k pdf).

Though the product picture shows two gearmotors, this product is for a single motor.



Size: 70.0 × 22.4 × 21.0 mm1
Weight: 33 g

General specifications

Gear ratio: 143:1
Free-run speed @ 6V: 78 rpm
Free-run current @ 6V: 52 mA
Stall current @ 6V: 700 mA
Stall torque @ 6V: 76 oz·in
Free-run speed @ 3V: 40 rpm
Free-run current @ 3V: 50 mA
Stall current @ 3V: 400 mA
Stall torque @ 3V: 44 oz·in


See drawing for detailed dimensions.


Documentation and other information

Comparison of Solarbotics Gearmotors (GM Series)

Table comparing specifications for the Solarbotics GM motors that we carry.

File downloads

GM9 performance datasheet (163k pdf)
Dimensions (in) (100k pdf)
Dimension diagram for the Solarbotics GM9 gearmotor in inches.
Dimensions (mm) (100k pdf)
Dimension diagram for the Solarbotics GM9 gearmotor in millimeters.
GM9 Solidworks files (2MB zip)


SKU PL-188
Brand Solarbotics

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