6.3:1 Metal Gearmotor 37Dx65L mm 12V with 64 CPR Encoder (Helical Pinion), 4757

£39.61 £33.01

Measuring 37 mm (1.46″) in diameter, these brushed DC gearmotors are the largest and most powerful we carry.

They are available in a range of gear ratios from 6.3:1 to 150:1 and with 12 V or 24 V motors, and all versions are available with integrated 64 CPR quadrature encoders on the motor shafts. 

Please contact us if you require a different configuration.

voltage no-load performance stall extrapolation
12V  1600 RPM, 200mA  3.0kg.cm (42 oz.in), 5.5A

This gearmotor is a powerful 12V brushed DC motor with a 6.25:1 metal gearbox and an integrated quadrature encoder that provides a resolution of 64 counts per revolution of the motor shaft, which corresponds to 400 counts per revolution of the gearbox’s output shaft.

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.

 Size 37D x 65L mm (1) 
 Weight  190g
 Shaft Diameter  6mm (2)
 Gear Ratio  6.25:1
 No load speed @ 12V  1600rpm
 No load current @ 12V  0.2A
 Stall current @ 12V  5.5A (3)
 Stall torque @ 12V  3.0 kg cm (3)
 Max output power @ 12V  12W
 No load speed @ 6V  800 rpm (4)
 No load current @ 6 V  0.15A (4)
 Stall current @ 6V  3.0A (4)
 Stall torque @ 6V  1.7kg cm (4)
 Motor type  12V
 Max efficiency @ 12V  47%
 Speed at max efficiency  1300rpm
 Torque at max efficiency  0.49 kg cm
 Current at max efficiency  1.2A
 Output power at max efficiency  6.4 W
 Lead length  20cm (5)
 Encoders  Yes
 Encoder resolution  64 CPR


(1)  Length measurement is from gearbox face plate to back of encoder cap (it does not include the output shaft). 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 motor will run at 6 V but is intended for operation at 12 V.

(5)  May vary by a few centimeters.

Datasheet for Pololu 37D Metal Gearmotors

Dimension diagrams of the Pololu 37D mm Metal Gearmotors

3D models of 37D mm gearmotors

Recommended links

MATLAB script to plot motor performance curves for Pololu brushed DC gearmotors

This MATLAB script, written by Ali Asgher Mansoor Habiby, plots speed, power, current draw, and efficiency as they vary with torque when you input the gearmotor specifications. It also prints the resistance of the motor, and the current draw and torque at which maximum efficiency and maximum power occur.