250:1 12V HPCB - Micro Metal Gearmotor

This gearmotor is a miniature high-power, 12 V brushed DC motor with long-life carbon brushes and a 248.98:1 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.

Key specifications:

Gearmotor Dimensions

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

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.

Note: The gearbox on the 1000:1 and 1000:1 HP micro metal gearmotors is 12.5 mm long. All of the other micro metal gearmotors have 9mm-long gearboxes, as shown in the above dimension diagram.

Motor Accessories

• Wheels and Hubs: The micro metal gearmotor’s output shaft matches our assortment of Pololu wheels and the Solarbotics RW2 rubber wheel. You can also use the Pololu universal mounting hub to mount custom wheels and mechanism to the micro metal gearmotor’s output shaft.

Pololu Wheel 32×7mm Pair - Black	Pololu Wheel 32×7mm Pair - White	Pololu Wheel 40×7mm Pair - Red

Black Pololu Wheels with 90, 80, 70, 60, 40, and 32 mm diameters (other colors available).

• Mounting Brackets: Our mounting bracket (also available in white) and extended mounting bracket are specifically designed to securely mount the gearmotor while enclosing the exposed gears. We recommend the extended mounting bracket for wheels with recessed hubs, such as the Pololu wheel 42×19mm.

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 Encoder: We offer a quadrature encoder for this motor that works with our extended bracket and 42×19mm wheel and provides feedback about wheel rotation (direction and speed). The encoder can be purchased as an individual unit or as part of an encoder set that includes two encoders, a pair of extended brackets, and a pair of 42×19mm wheels—just pick the particular micro metal gearmotor that best suits your application and you have a solution for closed-loop motor control.

Magnetic Encoder assembled on a Micro Metal Gearmotor with Extended Motor Shaft	Magnetic Encoder assembled on a Micro Metal Gearmotor with Extended Motor Shaft	Magnetic Encoder with Side-Entry Connector assembled on a Micro Metal Gearmotor with Extended Motor Shaft

• Motor Controllers: We have a number of motor controllers that make it easy to drive these micro metal gearmotors, including our qik 2s9v1 dual serial motor controller and our programmable Baby Orangutan and Orangutan SVP robot controllers. The inexpensive qik 2s9v1 allows variable speed and direction control of two small, brushed DC motors using a simple serial interface; the Orangutans combine a programmable Atmel AVR microcontroller and dual motor driver all in a single package and make interfacing with the motor drivers simple when you use our Pololu AVR library. All of the above controllers use the TB6612FNG dual motor driver, for which we also offer a simple carrier board.

DRV8838 Single Brushed DC Motor Driver Carrier.	Pololu A4990 Dual Motor Driver Shield for Arduino, bottom view.	DRV8835 dual motor driver carrier.