250:1 Metal Gearmotor 20Dx46L mm 6V CB with Extended Motor Shaft

These cylindrical brushed DC gearmotors are available in a wide range of gear ratios, from 25:1 up to 488:1, and with three different motors: 6 V and 12 V motors with long-life carbon brushes (CB), and a 6 V motor with shorter-life precious metal brushes. All three motors offer similar performances at their respective nominal voltages, just with the 12 V motor drawing approximately half the current of the 6 V motor and with the carbon brush versions having longer lifetimes than the one with precious metal brushes.

Specifications:

• Gear ratio: 250 : 1
• No-load speed @ 6V : 57 rpm
• No-load current @ 6V : 0.15 A
• Stall current @ 6V : 2.9 A
• Stall torque @ 6V : 12 kg·cm
• Max output power @ 6V : 1.8 W
• Extended motor shaft : Yes
• Long-life carbon brushes : Yes
• Motor type : 2.9A stall @ 6V CB (carbon brush)

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 : 0.62 A
• Output power at max efficiency : 1.0 W

Package Includes:

• 1x 250:1 Metal Gearmotor 20Dx46L mm 6V CB with Extended Motor Shaft

Documents / Downloads:

• Datasheet for Pololu 20D Metal Gearmotors
• Dimension diagram

Note: Stalling or overloading gearmotors can greatly decrease their lifetimes and even result in immediate damage. In order to avoid damaging the gearbox, recommend keeping continuously applied loads under 5 kg-cm (75 oz-in) for the versions with carbon brushes (12V CB and 6V CB) and under 3.5 kg-cm (50 oz-in) for the versions with precious metal brushes. 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.