25:1 Metal Gearmotor 20Dx42L mm LP

25:1 Metal Gearmotor 20Dx42L mm LP
Pololu item #: 1085 0 in stock

This product has been discontinued.

This 1.64" x 0.80" x 0.80" gearmotor is a high-quality, low-current motor with 25:1 metal gearbox. These units have a 0.276"-long, 4 mm-diameter D-shaped output shaft.

Key specs at 6 V: 470 RPM and 60 mA free-run, 7 oz-in (0.5 kg-cm) and 0.58 A stall.

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Pololu 20D mm gearmotor with bracket and hub.

Gearmotor Dimensions:

The face plate has two mounting holes threaded for M2.5 screws. You can use our custom-designed 20D metal gearmotor bracket (pictured to the right) to mount the gearmotor to your project via these mounting holes and the screws that come with the bracket.

Please note that the 20Dx44L mm line of gearmotors have output shafts with a diameter of 4 mm. The Pololu universal aluminum mounting hub for 4mm shafts can be used to mount custom wheels and mechanisms to the gearmotor’s output shaft.

The picture below shows the dimensions (in mm) of the 20D mm line of gearmotors. The value of X is 16.75 mm for this version.

25:1 and 67:1 20D mm metal gearmotor dimensions (units in mm). Note: this diagram only applies to the older and now-discontinued 25:1 and 67:1 gear ratio versions.


These motors are intended for use at 6 V. In general, these kinds of motors can run at voltages above and below this nominal voltage, so they should comfortably operate in the 3 – 9 V range. Lower voltages might not be practical, and higher voltages could start negatively affecting the life of the motor.

Note: This motor is a lower-current, lower-power version of our 25:1 metal gearmotor 20Dx44L mm.

Some of the Pololu metal gearmotors.


Specs for the metal gearmotors running at 6 V:

gearmotor gear ratio free-run RPM free-run current stall current     stall torque*
(oz-in / kg-cm)
      weight
(oz / g)
5:1 Micro 5:1 2500 50 mA 360 mA 1 / 0.1 0.35 / 10
10:1 Micro 10:1 1300 40 mA 360 mA 2 / 0.2 0.35 / 10
30:1 Micro 30:1 440 40 mA 360 mA 4 / 0.3 0.35 / 10
50:1 Micro 50:1 250 40 mA 360 mA 6 / 0.4 0.35 / 10
100:1 Micro 100:1 120 40 mA 360 mA 10 / 0.7 0.35 / 10
150:1 Micro 150:1 85 40 mA 360 mA 15 / 1.1 0.35 / 10
210:1 Micro 210:1 60 40 mA 360 mA 19 / 1.3 0.35 / 10
250:1 Micro 250:1 50 30 mA 360 mA 22 / 1.6 0.35 / 10
298:1 Micro 298:1 45 30 mA 360 mA 25 / 1.8 0.35 / 10
5:1 Micro HP 5:1 6000 120 mA 1600 mA 2 / 0.1 0.35 / 10
10:1 Micro HP 10:1 3000 120 mA 1600 mA 4 / 0.3 0.35 / 10
30:1 Micro HP 30:1 1000 120 mA 1600 mA 8 / 0.6 0.35 / 10
50:1 Micro HP 50:1 625 100 mA 1600 mA 15 / 1.0 0.35 / 10
100:1 Micro HP 100:1 320 80 mA 1600 mA 25 / 1.8 0.35 / 10
150:1 Micro HP 150:1 200 70 mA 1600 mA 45 / 3.2 0.35 / 10
210:1 Micro HP 210:1 140 70 mA 1600 mA 65 / 4.7 0.35 / 10
250:1 Micro HP 250:1 120 70 mA 1600 mA 75 / 5.4 0.35 / 10
298:1 Micro HP 298:1 100 70 mA 1600 mA 90 / 6.5 0.35 / 10
24:1 Mini 24:1 410 70 mA 420 mA 4 / 0.3 0.80 / 27
100:1 Mini 100:1 140 90 mA 800 mA 15 / 1.0 0.80 / 27
35:1 Mini 35:1 350 70 mA 1500 mA 35 / 2.5 0.80 / 27
25:1 20Dx44L mm LP 25:1 470 60 mA 580 mA 7 / 0.5 1.70 / 48
25:1 20Dx44L mm 25:1 500 250 mA 3300 mA 40 / 2.9 1.70 / 48
67:1 20Dx45L mm 67:1 210 250 mA 3300 mA 57 / 4.1 1.80 / 51
154:1 20Dx47L mm 154:1 90 250 mA 3300 mA 122 / 8.8 1.85 / 52
19:1 37Dx52L mm 19:1 256 250 mA 2500 mA 40 / 2.9 6.40 / 180
29:1 37Dx52L mm 29:1 175 250 mA 2500 mA 55 / 4 6.40 / 180
50:1 37Dx54L mm 50:1 101 250 mA 2500 mA 85 / 6 6.60 / 187
67:1 37Dx54L mm 67:1 75 250 mA 2500 mA 100 / 7 6.60 / 187
100:1 37Dx57L mm 100:1 50 250 mA 2500 mA 110 / 8 6.80 / 193
122:1 37Dx57L mm 122:1 41 250 mA 2500 mA 125 / 9 6.80 / 193


* The stall torque should only be considered a rough estimate.