Pololu Metal DC Gearmotors » 20D Metal Gearmotors » 6V Carbon Brush (CB) 20D Gearmotors »
100:1 Metal Gearmotor 20Dx44L mm 6V CB
These small brushed 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 100:1 metal spur gearbox. The gearmotor is cylindrical with a diameter of 20 mm, and the D-shaped output shaft is 4 mm in diameter and extends 18 mm from the face plate of the gearbox.
Key specifications:
| voltage | no-load performance | stall extrapolation | 
|---|---|---|
| 6 V | 140 RPM, 150 mA | 5.4 kg⋅cm (75 oz⋅in), 2.9 A | 
Alternatives available with variations in these parameter(s): gear ratio motor type extended motor shaft? Select variant…
 Compare all products in 6V Carbon Brush (CB) 20D Gearmotors.
Compare all products in 6V Carbon Brush (CB) 20D Gearmotors.
| Description | Specs (17) | Pictures (14) | Resources (3) | FAQs (3) | On the blog (0) | Distributors (1) | 
|---|
Dimensions
| Size: | 20D × 46.2L mm1 | 
|---|---|
| Weight: | 46 g | 
| Shaft diameter: | 4 mm2 | 
General specifications
| Gear ratio: | 100:1 | 
|---|---|
| No-load speed @ 6V: | 140 rpm | 
| No-load current @ 6V: | 0.15 A | 
| Stall current @ 6V: | 2.9 A3 | 
| Stall torque @ 6V: | 5.4 kg·cm3 | 
| Max output power @ 6V: | 2.0 W | 
| Extended motor shaft?: | N | 
| Long-life carbon brushes?: | Y | 
| Motor type: | 2.9A stall @ 6V CB (carbon brush) | 
Performance at maximum efficiency
| Max efficiency @ 6V: | 30 % | 
|---|---|
| Speed at max efficiency: | 120 rpm | 
| Torque at max efficiency: | 0.10 kg·cm | 
| Current at max efficiency: | 0.63 A | 
| Output power at max efficiency: | 1.1 W | 
Notes:
- 1
- Not including output shaft; output shaft adds 18 mm to the total length.
- 2
- D shaft.
- 3
- Stalling is likely to damage the gearmotor. Stall parameters come from a theoretical extrapolation of performance at loads far from stall. As the motor heats up, as happens as it approaches an actual stall, the stall torque and current decrease.








































