75:1 Micro Metal Gearmotor HPCB 12V with Extended Motor Shaft

This gearmotor is a miniature high-power, 12 V brushed DC motor with long-life carbon brushes and a 75.81:1 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 .

AUD$ 35.95

In stock in Australia  

Shipping from $7.90

+195 more from our supplier in 7-10 days

Our Code: SKU-003687

Supplier Link: [Pololu MPN:3051]


Description

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-coloured 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).

Micro metal gearmotor HPCB with long-life carbon brushes (left) next to one with precious metal brushes

Micro metal gearmotor HPCB long-life carbon brushes (left) next to micro metal gearmotor HP precious metal brushes (right)

Magnetic Encoder Kit for Micro Metal Gearmotors assembled with ribbon cable wires

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 magnetic encoder 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 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.

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 6000 RPM 2 oz-in 5:1 HPCB 5:1 HPCB dual-shaft
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 5:1 HP dual-shaft
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 210:1 HP dual-shaft
120 RPM 60 oz-in 250:1 HP 250:1 HP dual-shaft
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 4400 RPM 1.5 oz-in 5:1 MP dual-shaft
2200 RPM 3 oz-in 10:1 MP 10:1 MP dual-shaft
730 RPM 8 oz-in 30:1 MP 30:1 MP dual-shaft
420 RPM 12 oz-in 50:1 MP 50:1 MP dual-shaft
290 RPM 17 oz-in 75:1 MP 75:1 MP dual-shaft
220 RPM 21 oz-in 100:1 MP 100:1 MP dual-shaft
150 RPM 28 oz-in 150:1 MP 150:1 MP dual-shaft
100 RPM 36 oz-in 210:1 MP dual-shaft
90 RPM 41 oz-in 250:1 MP dual-shaft
75 RPM 46 oz-in 298:1 MP 298:1 MP dual-shaft
22 RPM 80 oz-in 1000:1 MP 1000:1 MP dual-shaft
low-power 360 mA 2500 RPM 1 oz-in 5:1 5:1 dual-shaft
1300 RPM 2 oz-in 10:1 10:1 dual-shaft
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 75:1 dual-shaft
120 RPM 12 oz-in 100:1 100:1 dual-shaft
85 RPM 17 oz-in 150:1 150:1 dual-shaft
60 RPM 27 oz-in 210:1 210:1 dual-shaft
50 RPM 32 oz-in 250:1 250:1 dual-shaft
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.

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 #3051

Exact gear ratio: ``(34×34×35×38) / (13×12×13×10) ~~ bb(75.81:1)``

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 (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

Pololu wheel 32x7mm on a micro metal gearmotor

Black Pololu 70x8mm wheel 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

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: We offer several quadrature encoders that work with our micro metal gearmotors.

Magnetic Encoder Kit for Micro Metal Gearmotors assembled with ribbon cable wires

Example of an installed micro metal gearmotor reflective optical encoder

Encoder for Pololu wheel 42x19mm with wheel, motor, and bracket

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

DRV8838 Single Brushed DC Motor Driver Carrier

Pololu A4990 Dual Motor Driver Shield for Arduino, bottom view

DRV8835 dual motor driver carrier

We also incorporate these motors into some of our products, including our Zumo robot and 3pi robot :

Assembled Zumo 32U4 robot

Pololu 3pi robot

Selecting the Right Gearmotor

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

Some of the Pololu metal gearmotors.


Specifications

Dimensions

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

General specifications

Gear ratio: 75.81:1
Free-run speed @ 6V: 200 rpm3
Stall current @ 6V: 400 mA4
Stall torque @ 6V: 11 oz·in4
Free-run speed @ 12V: 400 rpm
Free-run current @ 12V: 100 mA
Stall current @ 12V: 800 mA
Stall torque @ 12V: 22 oz·in
Extended motor shaft?: Y
Long-life carbon brushes?: Y
Motor type: 0.8A stall @ 12V (HPCB 12V - carbon brush)

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.
4
This motor will run at 6 V but is intended for operation at 12 V.

Resources

File downloads

micro metal gearmotor dimension diagram (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.

Recommended links

MATLAB script to plot motor performance curves for Pololu brushed DC gearmotors
This MATLAB script, written by Ali Asgher Mansoor Habiby, plots speed, power, current draw, and efficiency as they vary with torque when you input the gearmotor specifications. It also prints the resistance of the motor, and the current draw and torque at which maximum efficiency and maximum power occur.

FAQs

I need additional information about this motor; do you have a datasheet?

No; the information we have available for this motor can be found on its product page. However, you can approximate various additional motor parameters from the information found in the “Specs” tab.

The electrical resistance of the motor can be approximated by dividing the rated voltage by the stall current (at the rated voltage). The electromotive force constant (Ke) can be approximated by dividing the rated voltage by the free-run speed (at the rated voltage). To approximate the motor torque constant (Kt), you can divide the stall torque by the stall current.

For pretty much any DC motor, the current, speed, power, and efficiency curves as a function of torque will look like those in the graph below (assuming motor voltage and temperature are constant):

The current and speed curves are approximately linear, and the product pages for our motors provide the approximate end points for these lines: (0 torque, no-load current) and (stall torque, stall current) for the red line, and (0 torque, no-load speed) and (stall torque, 0 speed) for the blue line.

The orange output power curve is the product of the speed and the torque, which results in an inverted parabola with its peak at 50% of the stall torque.

The green efficiency curve is the output power divided by the input power, where the input power is current times voltage. The voltage is constant, so you can divide the output power curve by the current line to get the general shape of the efficiency curve, which in turn lets you identify the torque, speed, and current that correspond to max efficiency.

There are many programs out there that you can use to generate these curves. For example, if you have access to MATLAB, you can use this customer-created MATLAB script to generate these motor plots for you from the specifications we provide for each gearmotor.

Note: A good general rule of thumb is to keep the continuous load on a DC motor from exceeding approximately 20% to 30% of the stall torque. Stalling gearmotors can greatly decrease their lifetimes, occasionally resulting in immediate damage to the gearbox or thermal damage to the motor windings or brushes. Do not expect to be able to safely operate a brushed DC gearmotor all the way to stall. The safe operating range will depend on the specifics of the gearmotor itself.

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