298:1 Micro Metal Gearmotor HP with Extended Motor Shaft

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 Pololu's 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.

Please see the micro metal gearmotor datasheet (5MB pdf) for more information, including detailed performance graphs for each micro metal gearmotor version. You can also use Pololu's dynamically sortable micro metal gearmotor comparison table to search for the gearmotor that offers the best combination of speed, torque, and current draw for your particular application. A more basic comparison table is available below.

Rated Voltage	Motor Type	Stall Current	No-Load Current	No-Load Speed (RPM)	Extrapolated Stall Torque		Max Power (W)	Single-Shaft (Gearbox Only)	Dual-Shaft (Gearbox & Motor)
					(kg · cm)	(oz · in)
12 V	high-power, carbon brushes (HPCB)	0.75 A	100 mA	6800	0.09	1.3	–	5:1 HPCB 12V	5:1 HPCB 12V dual-shaft
			80 mA	3400	0.17	2.4	1.5	10:1 HPCB 12V	10:1 HPCB 12V dual-shaft
				2200	0.25	3.5	1.4	15:1 HPCB 12V	15:1 HPCB 12V dual-shaft
				1100	0.39	5.4	1.1	30:1 HPCB 12V	30:1 HPCB 12V dual-shaft
				650	0.67	9.3	1.1	50:1 HPCB 12V	50:1 HPCB 12V dual-shaft
				450	1.0	14	1.1	75:1 HPCB 12V	75:1 HPCB 12V dual-shaft
				330	1.3	18	1.1	100:1 HPCB 12V	100:1 HPCB 12V dual-shaft
				220	1.8	25	1.0	150:1 HPCB 12V	150:1 HPCB 12V dual-shaft
				160	2.5	35	1.0	210:1 HPCB 12V	210:1 HPCB 12V dual-shaft
				130	3.0	42	1.1	250:1 HPCB 12V	250:1 HPCB 12V dual-shaft
				110	3.3	46	1.0	298:1 HPCB 12V	298:1 HPCB 12V dual-shaft
				85	5.0	69	1.1	380:1 HPCB 12V	380:1 HPCB 12V dual-shaft
				35	10	140	–	1000:1 HPCB 12V	1000:1 HPCB 12V dual-shaft
6 V	high-power, carbon brushes (HPCB)	1.5 A	170 mA	6500	0.09	1.3	–	5:1 HPCB 6V	5:1 HPCB 6V dual-shaft
			150 mA	3300	0.17	2.4	1.3	10:1 HPCB 6V	10:1 HPCB 6V dual-shaft
				2100	0.25	3.5	1.3	15:1 HPCB 6V	15:1 HPCB 6V dual-shaft
				1100	0.45	6.2	1.2	30:1 HPCB 6V	30:1 HPCB 6V dual-shaft
				650	0.74	10	1.2	50:1 HPCB 6V	50:1 HPCB 6V dual-shaft
				430	1.1	15	1.3	75:1 HPCB 6V	75:1 HPCB 6V dual-shaft
				330	1.6	22	1.3	100:1 HPCB 6V	100:1 HPCB 6V dual-shaft
				220	2.0	28	1.1	150:1 HPCB 6V	150:1 HPCB 6V dual-shaft
				160	2.8	39	1.1	210:1 HPCB 6V	210:1 HPCB 6V dual-shaft
				130	3.2	44	1.1	250:1 HPCB 6V	250:1 HPCB 6V dual-shaft
				110	3.4	47	1.0	298:1 HPCB 6V	298:1 HPCB 6V dual-shaft
				85	5.0	69	1.1	380:1 HPCB 6V	380:1 HPCB 6V dual-shaft
				33	11	150	–	1000:1 HPCB 6V	1000:1 HPCB 6V dual-shaft
6 V	high-power (HP)	1.6 A	120 mA	6100	0.11	1.5	–	5:1 HP 6V	5:1 HP 6V dual-shaft
			100 mA	3100	0.22	3.0	1.6	10:1 HP 6V	10:1 HP 6V dual-shaft
				2000	0.30	4.2	1.5	15:1 HP 6V	15:1 HP 6V dual-shaft
				1000	0.57	7.9	1.5	30:1 HP 6V	30:1 HP 6V dual-shaft
				590	0.86	12	1.3	50:1 HP 6V	50:1 HP 6V dual-shaft
				410	1.3	18	1.4	75:1 HP 6V	75:1 HP 6V dual-shaft
				310	1.7	24	1.3	100:1 HP 6V	100:1 HP 6V dual-shaft
				210	2.4	33	1.2	150:1 HP 6V	150:1 HP 6V dual-shaft
				150	3.0	42	1.1	210:1 HP 6V	210:1 HP 6V dual-shaft
				120	3.4	47	1.1	250:1 HP 6V	250:1 HP 6V dual-shaft
				100	4.0	56	1.1	298:1 HP 6V	298:1 HP 6V dual-shaft
				84	5.5	76	1.1	380:1 HP 6V	380:1 HP 6V dual-shaft
				31	12	170	–	1000:1 HP 6V	1000:1 HP 6V dual-shaft
6 V	medium-power (MP)	0.67 A	80 mA	4400	0.06	0.8	–	5:1 MP 6V	5:1 MP 6V dual-shaft
			70 mA	2200	0.11	1.5	–	10:1 MP 6V	10:1 MP 6V dual-shaft
				1400	0.20	2.8	0.70	15:1 MP 6V	15:1 MP 6V dual-shaft
				720	0.33	4.6	0.57	30:1 MP 6V	30:1 MP 6V dual-shaft
				420	0.54	7.5	0.55	50:1 MP 6V	50:1 MP 6V dual-shaft
				290	0.78	11	0.54	75:1 MP 6V	75:1 MP 6V dual-shaft
				220	0.94	13	0.50	100:1 MP 6V	100:1 MP 6V dual-shaft
				150	1.3	18	0.48	150:1 MP 6V	150:1 MP 6V dual-shaft
				100	1.7	24	0.46	210:1 MP 6V	210:1 MP 6V dual-shaft
				88	2.2	31	0.48	250:1 MP 6V	250:1 MP 6V dual-shaft
				73	2.4	33	0.44	298:1 MP 6V	298:1 MP 6V dual-shaft
				57	3.6	50	0.53	380:1 MP 6V	380:1 MP 6V dual-shaft
				22	6.7	93	–	1000:1 MP 6V	1000:1 MP 6V dual-shaft
6 V	low-power (LP)	0.36 A	50 mA	2500	0.05	0.7	–	5:1 LP 6V	5:1 LP 6V dual-shaft
			40 mA	1300	0.10	1.4	–	10:1 LP 6V	10:1 LP 6V dual-shaft
				860	0.17	2.4	0.37	15:1 LP 6V	15:1 LP 6V dual-shaft
				450	0.29	4.0	0.31	30:1 LP 6V	30:1 LP 6V dual-shaft
				270	0.44	6.1	0.29	50:1 LP 6V	50:1 LP 6V dual-shaft
				180	0.64	8.9	0.29	75:1 LP 6V	75:1 LP 6V dual-shaft
				130	0.74	10	0.25	100:1 LP 6V	100:1 LP 6V dual-shaft
				90	1.1	15	0.25	150:1 LP 6V	150:1 LP 6V dual-shaft
				65	1.6	22	0.25	210:1 LP 6V	210:1 LP 6V dual-shaft
				54	1.7	24	0.23	250:1 LP 6V	250:1 LP 6V dual-shaft
				45	2.0	28	0.22	298:1 LP 6V	298:1 LP 6V dual-shaft
				36	2.9	40	0.27	380:1 LP 6V	380:1 LP 6V dual-shaft
				13	5.5	76	–	1000:1 LP 6V	1000:1 LP 6V dual-shaft

Note: Stalling or overloading gearmotors can greatly decrease their lifetimes and even result in immediate damage. The recommended upper limit for instantaneous torque is 2.5 kg-cm (35 oz-in) for the 380:1 and 1000:1 gearboxes, and 2 kg-cm (25 oz-in) for all the other gear ratios; Pololu strongly advise keeping applied loads well under this limit. Stalls can also result in rapid (potentially on the order of seconds) thermal damage to the motor windings and brushes, especially for the versions that use high-power (HP and HPCB) motors; a general recommendation for brushed DC motor operation is 25% or less of the stall current.

In general, these kinds of motors can run at voltages above and below their nominal voltages; lower voltages might not be practical, and higher voltages could start negatively affecting the life of the motor.

Details for item #2218

Exact gear ratio: 25×34×37×35×3812×9×10×13×10≈297.92:125×34×37×35×3812×9×10×13×10˜297.92:1$\frac{25\times 34\times 37\times 35\times 38}{12\times 9\times 10\times 13\times 10}˜297.92:1$

This gearmotor is a miniature high-power, 6 V brushed DC motor with 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:

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).

Motor Accessories

• Wheels and hubs: The micro metal gearmotor’s output shaft matches Pololu's assortment of Pololu wheels and the Solarbotics RW2i rubber wheel. You can also use Pololu's Pololu universal mounting hubs to mount custom wheels and mechanism to the micro metal gearmotor’s output shaft, and you can use Pololu's 12mm hex wheel adapter to use this motor with many common hobby RC wheels.

Pololu Wheel 32×7mm on a Micro Metal Gearmotor.

Black Pololu Wheel 70×8mm on a Pololu Micro Metal Gearmotor.

A pair of Pololu universal aluminum mounting hubs for 3 mm diameter shafts.

12mm Hex Wheel Adapter for 3mm Shaft on a Micro Metal Gearmotor.

• Mounting brackets: Pololu's mounting bracket (also available in white) and extended mounting bracket are specifically designed to securely mount the gearmotor while enclosing the exposed gears. Pololu recommend the extended mounting bracket for wheels with recessed hubs, such as the Pololu wheel 42×19mm. Pololu's micro metal gearmotors will also work with Pololu's 15.5D mm metal gearmotor bracket pair.

Black micro metal gearmotor mounting bracket pair with included screws and nuts.

White micro metal gearmotor mounting bracket pair with included screws and nuts.

Pololu micro metal gearmotor bracket extended with micro metal gearmotor.

• Quadrature encoders: Pololu offer several quadrature encoders that work with Pololu's micro metal gearmotors.

Magnetic Encoder with Side-Entry Connector assembled on a Micro Metal Gearmotor with Extended Motor Shaft (JST cable not included).

Example of an installed micro metal gearmotor reflective optical encoder.

Note: The HPCB versions of Pololu's micro metal gearmotors are not compatible with Pololu's #2590 and #2591 optical encoders or Pololu's older #2598 magnetic encoders (the terminals are too wide to fit through the corresponding holes in the encoder boards). However, they are compatible with Pololu's newer #3081, #4760, and #4761 magnetic encoders.

• Motor controllers and drivers: Pololu have a number of motor controllers, motor drivers, and robot controllers that make it easy to drive these micro metal gearmotors. For the 6 V micro metal gearmotors, consider the DRV8838 single-channel motor driver carrier, the DRV8833 dual motor driver carrier, and DRV8835 dual motor driver carrier (or DRV8835 shield for Arduino). For the 12 V micro metal gearmotors, consider the MAX14870 single-channel motor driver carrier, DRV8801 single-channel motor driver carrier, and A4990 dual motor driver carrier (or A4990 shield for Arduino).

DRV8838 Single Brushed DC Motor Driver Carrier.

Pololu A4990 Dual Motor Driver Shield for Arduino, bottom view.

DRV8835 dual motor driver carrier.

• Current sensors: Pololu have an assortment of Hall effect-based current sensors to choose from for those who need to monitor motor current:

ACS711EX current sensor carrier -15.5A to +15.5A.

ACS714 current sensor carrier -5A to +5A.

Pololu also incorporate these motors into some of Pololu's products, including Pololu's Zumo robot and 3pi robot :

Assembled Zumo 32U4 robot.

Original Pololu 3pi robot.

Selecting the Right Gearmotor

Pololu offer a wide selection of metal gearmotors that offer different combinations of speed and torque. Pololu's metal gearmotor comparison table can help you find the motor that best meets your project’s requirements.

People often buy this product together with:

Pololu Micro Metal Gearmotor Bracket Pair - Black

Pololu Micro Metal Gearmotor Bracket Extended Pair

100:1 Micro Metal Gearmotor HP 6V with Extended Motor Shaft

Dimensions

General specifications

Performance at maximum efficiency

Notes:

1

Output shafts add 14 mm to the 26 mm length.

2

D shaft.

3

Typical; ±20%.

4

Typical, ±50%; no-load current depends on internal friction, which is affected by many factors, including ambient temperature and duration of motor operation.

5

This is a theoretical value; stalling the gearbox output shaft will damage the gearbox.

File downloads

• Datasheet for Pololu Micro Metal Gearmotors (5MB pdf)

• Dimension diagrams of Pololu Micro Metal Gearmotors (262k pdf)

• 3D model of a Micro Metal Gearmotor with Extended Motor Shaft and a #1086 bracket (4MB step)

  3D model of a Micro Metal Gearmotor with Extended Motor Shaft and a #1086 bracket (or #989 bracket, which is just a black version of the #1086).

• 3D model of a Micro Metal Gearmotor and a #1086 bracket (4MB step)

  3D model of a Micro Metal Gearmotor and a #1086 bracket (or #989 bracket, which is just a black version of the #1086).

• 3D model of Micro Metal Gearmotors (single-shaft, precious metal brushes, not 1000:1) (11MB step)

  3D model of low-power, medium-power, high-power Pololu Micro Metal Gearmotors. This diagram does not apply to the HPCB versions, dual-shaft versions, or 1000:1 gear ratios.

• 3D model of Micro Metal Gearmotors with extended motor shafts (precious metal brushes, not 1000:1) (11MB step)

  3D model of low-power, medium-power, high-power Pololu Micro Metal Gearmotors with extended motor shafts. This diagram does not apply to the HPCB versions, single-shaft versions, or 1000:1 gear ratios.

• 3D model of 1000:1 Micro Metal Gearmotors (single-shaft, precious metal brushes) (14MB step)

  3D model of Pololu Micro Metal Gearmotors with 1000:1 gearboxes. This diagram does not apply to the HPCB versions, dual-shaft versions, or other gear ratios.

• 3D model of 1000:1 Micro Metal Gearmotors with extended motor shafts (precious metal brushes) (14MB step)

  3D model of Pololu Micro Metal Gearmotors with 1000:1 gearboxes and extended motor shafts. This diagram does not apply to the HPCB versions, single-shaft versions, or other gear ratios.

• 3D model of HPCB Micro Metal Gearmotors (single-shaft, carbon brushes, not 1000:1) (11MB step)

  3D model of high-power carbon brush (HPCB) Pololu Micro Metal Gearmotors. This diagram does not apply to precious metal brush (i.e. non-HPCB) versions, dual-shaft versions, or 1000:1 gear ratios.

• 3D model of HPCB Micro Metal Gearmotors with extended motor shafts (carbon brushes, not 1000:1) (11MB step)

  3D model of high-power carbon brush (HPCB) Pololu Micro Metal Gearmotors. This diagram does not apply to precious metal brush (i.e. non-HPCB) versions, single-shaft versions, or 1000:1 gear ratios.

• 3D model of 1000:1 HPCB Micro Metal Gearmotors (single-shaft, carbon brushes) (14MB step)

  3D model of high-power carbon brush (HPCB) Pololu Micro Metal Gearmotors with 1000:1 gearboxes. This diagram does not apply to precious metal brush (i.e. non-HPCB) versions, dual-shaft versions, or other gear ratios.

• 3D model of 1000:1 HPCB Micro Metal Gearmotors with extended motor shafts (carbon brushes) (14MB step)

  3D model of high-power carbon brush (HPCB) Pololu Micro Metal Gearmotors with 1000:1 gearboxes and extended motor shafts. This diagram does not apply to precious metal brush (i.e. non-HPCB) versions, single-shaft versions, or other gear ratios.