Pololu 4890 378:1 Metal Gearmotor 25Dx73L mm LP 12V with 48 CPR Encoder
This gearmotor consists of a low-power, 12 V brushed DC motor combined with a 377.93:1 metal spur gearbox, and it has an integrated 48 CPR quadrature encoder on the motor shaft, which provides 18,140.79 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).
|voltage ||no-load performance ||stall extrapolation |
|12 V ||14 RPM, 100 mA ||23 kg⋅cm (320 oz⋅in), 1.1 A |
|Size: ||25D x 73L mm1 |
|Weight: ||110 g |
|Shaft diameter: ||4 mm |
|Gear ratio: ||377.93:1 |
|No-load speed @ 12V: ||14 rpm |
|No-load current @ 12V: ||100 mA |
|Stall current @ 12V: ||1100 mA |
|Stall torque @ 12V: ||320 oz·in2 |
|No-load speed @ 6V: ||7 rpm3 |
|Stall current @ 6V: ||550 mA3 |
|Stall torque @ 6V: ||160 oz·in3 |
|Lead length: ||8 in4 |
|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 is a theoretical value; stalling the gearbox output shaft is likely to damage the gearbox.
- This motor will run at 6 V but is intended for operation at 12 V.
- May vary by a few inches.