20.4:1 Metal Gearmotor 25Dx65L mm HP 12V with 48 CPR Encoder
These cylindrical brushed DC gearmotors are available in a wide range of gear ratios and with five different motors (two power levels of 6V motors and three power levels of 12V motors). The gearmotors all have the same 25mm diameter case and 4mm 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). The motor and encoder portion is available by itself (no gearbox) for each combination of power level and nominal operating voltage, and versions without the encoder are also available. See the25D metal gearmotor datasheet(2MB pdf) for more information, including detailed performance graphs for each gearmotor version. You can also use our dynamically sortable25D gearmotor comparison tableto search for the version that offers the best combination of speed, torque, and current draw for your particular application
Using the encoder
A two-channel Hall effect encoder is used to sense the rotation of a magnetic disk on a rear protrusion of the motor shaft. The quadrature encoder provides a resolution of 48 counts per revolution of the motor shaft when counting both edges of both channels. To compute the counts per revolution of the gearbox output, multiply the gear ratio by 48. The motor/encoder has six color-coded, 8″ (20cm) leads terminated by a 1×6 female header with a 0.1″ pitch, as shown in the main product picture. This header works with standard0.1″ male headersand our malejumperandprecrimped wires. If this header is not convenient for your application, you can pull the crimped wires out of the header or cut the header off. The following table describes the wire functions:
| Color | Function |
|---|---|
| Red | motor power (connects to one motor terminal) |
| Black | motor power (connects to the other motor terminal) |
| Green | encoder GND |
| Blue | encoder Vcc (3.5V to 20V) |
| Yellow | encoder A output |
| White | encoder B output |
Dimensions
| Size: | 25D x 65L mm1 |
|---|---|
| Weight: | 98 g |
| Shaft diameter: | 4 mm2 |
General specifications
| Gear ratio: | 20.4:1 |
|---|---|
| No-load speed @ 12V: | 500 rpm3 |
| No-load current @ 12V: | 0.30 A4 |
| Stall current @ 12V: | 5.0 A5 |
| Stall torque @ 12V: | 7.4 kg·cm5 |
| Max output power @ 12V: | 9.4 W |
| No-load speed @ 6V: | 250 rpm6 |
| Stall current @ 6V: | 2.5 A6 |
| Stall torque @ 6V: | 3.7 kg·cm6 |
| Motor type: | 12V, 5.0A stall (HP 12V) |