131:1 Metal Gearmotor 37Dx73L mm With 64 Cpr Encoder

131:1 Metal Gearmotor 37Dx73L mm with 64 CPR Encoder  is a powerful 12V brushed DC motor with a 131.25:1 metal gearbox and an integrated quadrature encoder.It has a resolution of 64 counts per revolution of the motor shaft, which corresponds to 8400 counts per revolution of the gearbox’s output shaft. These units have a 0.61"-long, 6 mm-diameter D-shaped output shaft. This gearmotor is also available without an encoder.These motors are intended for use at 12 V, though in general, these kinds of motors can run at voltages above and below the nominal voltage (they can begin rotating at voltages as low as 1 V). Lower voltages might not be practical, and higher voltages could start negatively affecting the life of the motor.

Specifications:

•   Gear ratio:     131:1
•   Free-run speed @ 6V:     40 rpm2
•   Free-run current @ 6V:     250 mA2
•   Stall current @ 6V:     2500 mA2
•   Stall torque @ 6V:     125 oz·in2
•   Free-run speed @ 12V:     80 rpm
•   Free-run current @ 12V:     300 mA
•   Stall current @ 12V:     5000 mA
•   Stall torque @ 12V:     250 oz·in
•   Lead length:     11 in

Dimensions:

•   Size:     37mm Diameter x 72.5Length mm
•   Weight:     250 g
•   Shaft diameter:     6 mm

Note: Stalling or overloading gearmotors can greatly decrease their lifetimes and even result in immediate damage. Stalls can also result in rapid (potentially on the order of seconds) thermal damage to the motor windings and brushes; a general recommendation for brushed DC motor operation is 25% or less of the stall current.

Resources:

•   Dimension diagram of the Pololu 37D mm Metal Gearmotors
•   3D models of 37D mm gearmotors
•   MATLAB script to plot motor performance curves for Pololu brushed DC gearmotors