These small brushed Pololu 20D DC gearmotors can deliver a lot of power for their size. This version has a 6V brushed DC motor with long-life carbon brushes combined with a 250:1 metal spur gearbox. The gearmotor is cylindrical with a diameter of 20mm, and the D-shaped output shaft is 4mm in diameter and extends 18mm from the faceplate of the gearbox.
We also stock 25:1 and 100:1 versions of this motor.
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.
Note: Stalling or overloading gearmotors can greatly decrease their lifetimes and even result in immediate damage. In order to avoid damaging the gearbox, we recommend keeping continuously applied loads under 5 kg-cm (75 oz-in). Stalls can also result in rapid (potentially on the order of seconds) thermal damage to the motor windings and brushes, especially for motors like this that can deliver a lot of power for their size; a general recommendation for brushed DC motors is to limit continuous current to approximately 25% of the stall current.
|No-load speed @ 6V||57 rpm|
|No-load current @ 6V||0.15A|
|Stall current @ 6V||2.9 A|
|Stall torque @ 6V||12 kg·cm|
|Max output power @ 6V||1.8W|
|Extended motor shaft?||N|
|Long-life carbon brushes?||Y|
|Motor type||2.9A stall @ 6V CB (carbon brush)|
|Size||20D × 47.7L mm|
Performance at Maximum Efficiency
|Max efficiency @ 6V||28%|
|Speed at max efficiency||47 rpm|
|Torque at max efficiency||2.1 kg·cm|
|Current at max efficiency||0.62A|
|Output power at max efficiency||1.0 W|
- Datasheet for Pololu 20D Metal gearmotors
- Dimension Diagrams for Pololu 20D Metal gearmotors
- 3D Models of Pololu 20D Gearmotors
The downloadable diagram shows the dimensions of the 20Dmm line of metal gearmotors (units are mm over [inches]).
Warning: Do not screw too far into the mounting holes as the screws can hit the gears. We recommend screwing no more than 3.5 mm (0.14″) into the M2.5 mounting holes.
- Gearmotor Face Plate - The gearmotor face plate has two mounting holes threaded for M2.5 screws, and you can use our custom-designed 20D mm metal gearmotor bracket to mount the gearmotor to your project via these mounting holes and the screws that come with the bracket.
Universal Mounting Hubs - The 4mm diameter gearbox output shaft works with Pololu universal aluminum mounting hub for 4mm shafts, which can be used to mount our larger Pololu wheels (60mm-, 70mm-, 80mm-, and 90mm-diameter) or custom wheels and mechanisms to the gearmotor’s output shaft.
Scooter Wheel Adaptors - You can use our 4mm scooter wheel adapters to mount many common skateboard, inline skate or scooter wheels to the gearmotor’s output shaft.
- 12mm Hex Wheel Adapter - For a general-purpose hex adapter, consider our 12mm hex wheel adapter, which lets you use this motor with many common hobby RC wheels.
Wild Thumper Wheels - These motors also work with the hex adapters included with the 120mm-diameter Wild Thumper wheels