These tiny brushed DC gearmotors are available in a wide range of gear ratios—from 5:1 up to 1000:1—and with five different motors: high-power 6 V and 12 V motors with long-life carbon brushes (HPCB), and high-power (HP), medium power (MP), and low power (LP) 6 V motors with shorter-life precious metal brushes. The 6 V and 12 V HPCB motors offer the same performance at their respective nominal voltages, just with the 12 V motor drawing half the current of the 6 V motor. The 6 V HPCB and 6 V HP motors are identical except for their brushes, which only affect the lifetime of the motor.

The HPCB versions can be differentiated from versions with precious metal brushes by their copper-colored terminals. Note that the HPCB terminals are 0.5 mm wider than those on the other micro metal gearmotor versions (2 mm vs. 1.5 mm), and they are about 1 mm closer together (6 mm vs. 7 mm).

Versions of these gearmotors are also available with an additional 1 mm-diameter output shaft that protrudes from the rear of the motor. This 4.5 mm-long rear shaft rotates at the same speed as the input to the gearbox and offers a way to add an encoder, such as our encoders for micro metal gearmotors, to provide motor speed or position feedback.

Key specifications :

voltage	no-load performance	stall extrapolation
12 V	2200 RPM, 60 mA	0.25 kg⋅cm (3.5 oz⋅in), 0.75 A

This gearmotor is a miniature high-power, 12 V brushed DC motor with long-life carbon brushes and a 15.25:1 metal gearbox. It has a cross section of 10 × 12 mm, and the D-shaped gearbox output shaft is 9 mm long and 3 mm in diameter.

Dimensions :

Size:	10 × 12 × 26 mm
Weight:	9.5 g
Shaft diameter:	3 mm

General specifications :

Gear ratio:	15.25:1
No-load speed @ 12V:	2200 rpm
No-load current @ 12V:	0.06 A
Stall current @ 12V:	0.75 A
Stall torque @ 12V:	0.25 kg·cm
Max output power @ 12V:	1.4 W
No-load speed @ 6V:	1500 rpm³
No-load current @ 6V:	0.05 A³
Stall current @ 6V:	0.38 A³
Stall torque @ 6V:	0.09 kg·cm³
Long-life carbon brushes?:	Y
Motor type:	0.75A stall @ 12V (HPCB 12V - carbon brush)

Performance at maximum efficiency :

Max efficiency @ 12V:	37 %
Speed at max efficiency:	1700 rpm
Torque at max efficiency:	0.059 kg·cm
Current at max efficiency:	0.23 A
Output power at max efficiency:	1.0 W

In terms of size, these gearmotors are very similar to Sanyo’s popular 12 mm NA4S DC gearmotors, and gearmotors with this form factor are occasionally referred to as N20 motors. The versions with carbon brushes (HPCB) have slightly different terminal and end-cap dimensions than the versions with precious metal brushes, but all of the other dimensions are identical.

Documents:

Package Includes :

1 x Pololu 4788 / 4789 Micro Metal Gearmotor HPCB 12V - 15:1 gear ratio

Motor Specifications
Type	HPCB Micro Metal Gearmotor
Speed (RPM)	2200rpm
Torque	0.25 kg⋅cm
Gear Ratio	15:1
Shaft Diameter	3mm
Electrical Specifications
Maximum Operating Voltage	12V
Minimum Operating Current	0.75 A
Physical Attributes
Weight	9.5g
Dimensions	10 × 12 × 26 mm