210:1 Micro Metal Gearmotor

These tiny brushed DC gearmotors are intended for use at 6 V, though in general, these kinds of motors can run at voltages above and below this nominal voltage, so they should comfortably operate in the 3 – 9 V range (rotation can start at voltages as low as 0.5 V). Lower voltages might not be practical, and higher voltages could start negatively affecting the life of the motor. The micro metal gearmotors are available in a wide range of gear ratios—from 5:1 up to 1000:1—and with four different motors: high-power with long-life carbon brushes (HPCB), high-power with shorter-life precious metal brushes (HP), medium-power (MP), and low-power. The HPCB version (shown on the left in the picture below) can be differentiated from versions with precious metal brushes (shown on the right) by its 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).

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 comparison table for detailed specifications of all our micro metal gearmotors. This dynamically-sortable table can help you find the gearmotor that offers the best blend of speed, torque, and current-draw for your particular application. A more basic comparison table is available below.

Some versions of the gearmotors are 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 magnetic encoder for micro metal gearmotors (see the picture on the right), to provide motor speed or position feedback.

Motor Type	Stall Current @ 6 V	No-Load Speed @ 6 V	Approximate Stall Torque @ 6 V	Single-Shaft (Gearbox Only)	Dual-Shaft (Gearbox & Motor)
high-power, carbon brushes (HPCB)	1600 mA	3000 RPM	4 oz-in	10:1 HPCB	10:1 HPCB dual-shaft
		1000 RPM	9 oz-in	30:1 HPCB	30:1 HPCB dual-shaft
		625 RPM	15 oz-in	50:1 HPCB	50:1 HPCB dual-shaft
		400 RPM	22 oz-in	75:1 HPCB	75:1 HPCB dual-shaft
		320 RPM	30 oz-in	100:1 HPCB	100:1 HPCB dual-shaft
		200 RPM	40 oz-in	150:1 HPCB	150:1 HPCB dual-shaft
		140 RPM	50 oz-in	210:1 HPCB	210:1 HPCB dual-shaft
		120 RPM	60 oz-in	250:1 HPCB	250:1 HPCB dual-shaft
		100 RPM	70 oz-in	298:1 HPCB	298:1 HPCB dual-shaft
		32 RPM	125 oz-in	1000:1 HPCB	1000:1 HPCB dual-shaft
high-power (HP) (same specs as HPCB above)	1600 mA	6000 RPM	2 oz-in	5:1 HP
		3000 RPM	4 oz-in	10:1 HP	10:1 HP dual-shaft
		1000 RPM	9 oz-in	30:1 HP	30:1 HP dual-shaft
		625 RPM	15 oz-in	50:1 HP	50:1 HP dual-shaft
		400 RPM	22 oz-in	75:1 HP	75:1 HP dual-shaft
		320 RPM	30 oz-in	100:1 HP	100:1 HP dual-shaft
		200 RPM	40 oz-in	150:1 HP	150:1 HP dual-shaft
		140 RPM	50 oz-in	210:1 HP
		120 RPM	60 oz-in	250:1 HP
		100 RPM	70 oz-in	298:1 HP	298:1 HP dual-shaft
		32 RPM	125 oz-in	1000:1 HP	1000:1 HP dual-shaft
medium-power (MP)	700 mA	2200 RPM	3 oz-in	10:1 MP	10:1 MP dual-shaft
		730 RPM	8 oz-in	30:1 MP
		420 RPM	13 oz-in	50:1 MP
		290 RPM	17 oz-in	75:1 MP	75:1 MP dual-shaft
		220 RPM	19 oz-in	100:1 MP	100:1 MP dual-shaft
		150 RPM	24 oz-in	150:1 MP
		75 RPM	46 oz-in	298:1 MP
		25 RPM	80 oz-in	1000:1 MP	1000:1 MP dual-shaft
low-power	360 mA	2500 RPM	1 oz-in	5:1
		1300 RPM	2 oz-in	10:1
		440 RPM	4 oz-in	30:1	30:1 dual-shaft
		250 RPM	7 oz-in	50:1	50:1 dual-shaft
		170 RPM	9 oz-in	75:1
		120 RPM	12 oz-in	100:1	100:1 dual-shaft
		85 RPM	17 oz-in	150:1
		60 RPM	27 oz-in	210:1
		50 RPM	32 oz-in	250:1
		45 RPM	40 oz-in	298:1	298:1 dual-shaft
		14 RPM	70 oz-in	1000:1	1000:1 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 35 oz-in (2.5 kg-cm) for the 1000:1 gearboxes and 25 oz-in (2 kg*cm) for all the other gear ratios; we 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.

Details

Exact gear ratio: 25×34×34×35×3812×9×13×13×10≈210.59:1

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 (low-power, MP, and HP)

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

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