Pololu 4887 99:1 Metal Gearmotor 25Dx69L mm LP 12V with 48 CPR Encoder
This gearmotor consists of a low-power, 12 V brushed DC motor combined with a 98.78:1 metal spur gearbox, and it has an integrated 48 CPR quadrature encoder on the motor shaft, which provides 4741.44 counts per revolution of the gearbox’s output shaft. The gearmotor is cylindrical, with a diameter just under 25 mm, and the D-shaped output shaft is 4 mm in diameter and extends 12.5 mm from the face plate of the gearbox.
These cylindrical brushed DC gearmotors are available in a wide range of gear ratios and with five different motors (two power levels of 6 V motors and three power levels of 12 V motors). The gearmotors all have the same 25 mm diameter case 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 also available with an integrated 48 CPR quadrature encoder on the motor shaft. Please see the 25D metal gearmotor comparison table for detailed specifications of all our 25D 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.
Note: Stalling or overloading gearmotors can greatly decrease their lifetimes and even result in immediate damage. For these gearboxes, the recommended upper limit for instantaneous torque is 200 oz-in (15 kg-cm); . Stalls can also result in rapid (potentially on the order of a second) thermal damage to the motor windings and brushes, especially for the versions that use high-power (HP) motors; a general recommendation for brushed DC motor operation is 25% or less of the stall current.
|voltage ||no-load performance ||stall extrapolation |
|12 V ||55 RPM, 100 mA ||8 kg⋅cm (115 oz⋅in), 1.1 A |
|Size: ||25D x 69L mm1 |
|Weight: ||104 g |
|Shaft diameter: ||4 mm |
|Gear ratio: ||98.78:1 |
|No-load speed @ 12V: ||55 rpm |
|No-load current @ 12V: ||100 mA |
|Stall current @ 12V: ||1100 mA |
|Stall torque @ 12V: ||115 oz·in |
|No-load speed @ 6V: ||27 rpm2 |
|Stall current @ 6V: ||550 mA2 |
|Stall torque @ 6V: ||57 oz·in2 |
|Lead length: ||8 in3 |
|Motor type: ||1.1A stall @ 12V (LP 12V) |
|Encoders?: ||Y |
- Length measurement is from gearbox face plate to back of encoder cap (it does not include the output shaft). See dimension diagram for details.
- This motor will run at 6 V but is intended for operation at 12 V.
- May vary by a few inches.