298:1 Micro Metal Gearmotor HPCB 12V with Extended Motor Shaft Pololu 3056

This gearmotor is a miniature high-power, 12 V brushed DC motor with long-life carbon brushes and a 297.92:1 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. This version also has a 4.5 × 1 mm extended motor shaft.

Key specifications:

voltage	no-load performance	stall extrapolation
12 V	110 RPM, 60 mA	3.3 kg⋅cm (46 oz⋅in), 0.75 A

 

Overview

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 (shown on the left in the picture below) can be differentiated from versions with precious metal brushes (shown on the right) 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 (see the picture on the right), to provide motor speed or position feedback.

With the exception of the 1000:1 gear ratio versions, all of the micro metal gearmotors have the same physical dimensions, so one version can be easily swapped for another if your design requirements change.

 

Details for item #3056

Exact gear ratio: 25×34×37×35×3812×9×10×13×10≈297.92:1${\displaystyle \frac{25\times 34\times 37\times 35\times 38}{12\times 9\times 10\times 13\times 10}\approx 297.92:1}$

This gearmotor is a miniature high-power, 12 V brushed DC motor with long-life carbon brushes and a 297.92:1 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. This version also has a 4.5 × 1 mm extended motor shaft.

Key specifications:

voltage	no-load performance	stall extrapolation
12 V	110 RPM, 60 mA	3.3 kg⋅cm (46 oz⋅in), 0.75 A

Gearmotor Dimensions

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.

Dimensions of versions with carbon brushes (HPCB)

 

Dimensions of the Pololu micro metal gearmotors with carbon brushes (HPCB). Units are mm over [inches].

 

Dimensions of versions with precious metal brushes (LP, MP, and HP)

 

Dimensions of the Pololu micro metal gearmotors with precious metal brushes: low-power (LP), medium-power (MP), and high-power (HP). Units are mm over [inches].

 

These diagrams are also available as a downloadable PDF (262k pdf).

Dimensions

Size:	10 × 12 × 26 mm1
Weight:	9.5 g
Shaft diameter:	3 mm2

General specifications

Gear ratio:	297.92:1
No-load speed @ 12V:	110 rpm
No-load current @ 12V:	0.06 A
Stall current @ 12V:	0.75 A
Stall torque @ 12V:	3.3 kg·cm
Max output power @ 12V:	1.0 W
No-load speed @ 6V:	55 rpm3
No-load current @ 6V:	0.05 A3
Stall current @ 6V:	0.38 A3
Stall torque @ 6V:	1.7 kg·cm3
Extended motor shaft?:	Y
Long-life carbon brushes?:	Y
Motor type:	0.75A stall @ 12V (HPCB 12V - carbon brush)

Performance at maximum efficiency

Max efficiency @ 12V:	26 %
Speed at max efficiency:	87 rpm
Torque at max efficiency:	0.73 kg·cm
Current at max efficiency:	0.21 A
Output power at max efficiency:	0.65 W

Notes:

1) Output shafts add 14 mm to the 26 mm length.

2) D shaft.

3) This motor will run at 6 V but is intended for operation at 12 V.