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Pololu 131:1 Metal Gearmotor 37Dx57L mm 12V (Helical Pinion)

This gearmotor is a powerful brushed DC motor with 131.25:1 metal gearbox intended for operation at 12 V. The gearbox is composed mainly of spur gears, but it features helical gears for the first stage for reduced noise and improved efficiency. These units have a 16 mm-long, 6 mm-diameter D-shaped output shaft. 

Key specifications:

voltage no-load performance stall extrapolation
12 V 76 RPM, 150 mA 45 kg⋅cm (630 oz⋅in), 5.5 A




Dimensions of the 37D mm metal gearmotor (without encoder). Units are mm over [inches].



Size: 37D × 57L mm1
Weight: 195 g
Shaft diameter: 6 mm2

General specifications

Gear ratio: 131.25:1
No-load speed @ 12V: 76 rpm
No-load current @ 12V: 0.15 A
Stall current @ 12V: 5.5 A3
Stall torque @ 12V: 45 kg·cm3
Max output power @ 12V: 6 W4
No-load speed @ 6V: 38 rpm5
No-load current @ 6V: 0.1 A5
Stall current @ 6V: 3.0 A5
Stall torque @ 6V: 28 kg·cm5

Performance at maximum efficiency

Max efficiency @ 12V: 45 %
Speed at max efficiency: 66 rpm
Torque at max efficiency: 6.0 kg·cm
Current at max efficiency: 0.74 A
Output power at max efficiency: 4.1 W

General specifications

Encoders?: N


1: Length measurement is from gearbox face plate to back of motor (it does not include the output shaft or motor terminals). See dimension diagram for details.
2: D shaft.
3: Stalling is likely to damage the gearmotor. Stall parameters come from a theoretical extrapolation of performance at loads far from stall. As the motor heats up, as happens as it approaches an actual stall, the stall torque and current decrease.
4:This is the output power at the maximum recommended operating load of 10 kg⋅cm; higher power might be achievable for brief durations at higher loads (see performance graphs in the datasheet).
5: This motor will run at 6 V but is intended for operation at 12 V.

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