20D mm Metal Gearmotors
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. The gearmotors all have the same 20 mm diameter body and 4 mm diameter gearbox output shaft, so it is generally easy to swap one version for another if your design requirements change (though the length of the gearbox tends to increase with the gear ratio). All versions are available with an option extended motor shaft, which allows for the addition of encoders like our magnetic encoder for 20D mm metal gearmotors.
Alternatives available with variations in these parameter(s): gear ratio, motor type, extended motor shaft.
Please see the 20D mm metal gearmotor comparison table for detailed specifications of all our 20D mm metal gearmotors. This dynamically-sortable table can help you find the gearmotor that offers the best blend of speed, torque, and current-draw for your particular application. A more basic comparison table is available below:
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 50 oz-in (3.5 kg*cm) for the versions with precious metal brushes and under 70 oz-in (5 kg-cm) for the versions with carbon brushes (the ones with “CB” in the name). Stalls can also result in rapid (potentially on the order of a second) 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.
These 20D gearmotors have 12 V motors with a stall current of 1.6 A and a typical free-run current of 90 mA. They feature long-life carbon brushes and offer approximately the same performance at 12 V as the 6V CB versions offer at 6 V, just with half the current draw.