Pololu 298:1 Micro Metal Gearmotor (HP 6V)

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.

• Voltage: 6 V
• No-load Performance: 100 RPM, 70 mA
• Stall Extrapolation: 4.0 kg⋅cm (56 oz⋅in), 1.6 A

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 magnetic encoder for micro metal gearmotors, 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 (2MB pdf) for more information, including detailed performance graphs for each micro metal gearmotor version.

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 #994

Exact gear ratio: 25×34×37×35×3812×9×10×13×10≈297.92:1

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.

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

Documents:

• Datasheet for Pololu Micro Metal Gearmotors
• Dimension diagrams of Pololu Micro Metal Gearmotors
• MATLAB script to plot motor performance curves for Pololu brushed DC gearmotors