Discontinuation notice: Please consider our micro metal gearmotors for a wide selection of alternative gearmotors with the same form factor (but longer output shafts).
These miniature brushed DC metal gear motors have 3 mm diameter output shafts that mate fairly well with any 1/8-inch hole output device, including the Solarbotics RW2 high-traction rubber wheels. Alternatively, you can use the Pololu universal mounting hub to mount custom wheels and mechanism to the micro metal gearmotor’s output shaft.
The brass faceplates have two mounting holes threaded for 1.7 (dia) x 0.35 (mm/thd) x 4mm long screws (M1.7 × 4 mm), or you can use our mounting bracket, which is specifically designed to securely mount the gearmotor while enclosing the exposed gears.
These small motors come in a variety of gear ratios, have a compact size (1.14" x 0.39" x 0.47"), and weigh only 0.29 oz, making them a great choice for small robot designs — and controlling these low-current motors is a snap with our qik 2s9v1 dual serial motor controller.
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Solarbotics mini metal gearmotor dimensions (in mm). |
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You can download a pdf version of this drawing with imperial dimensions (119k pdf) or metric dimensions (118k pdf).
Specs for the Solarbotics mini metal gearmotors running at 6 V:
| gear motor | gear ratio | free-run RPM | free-run current | stall current | stall torque | price |
| GM18 | 30:1 | 566 | 48 mA | 500 mA | 7.29 oz-in | $19.75 |
| GM12a | 100:1 | 170 | 48 mA | 390 mA | 10.70 oz-in | $19.75 |
| GM13a | 150:1 | 113 | 40 mA | 370 mA | 14.97 oz-in | $19.75 |
| GM14a | 298:1 | 71 | 50 mA | 533 mA | 30.70 oz-in | $19.75 |
Specs for the similar, less expensive Pololu metal gearmotors running at 6 V:
| gearmotor | gear ratio | free-run RPM | free-run current | stall current | stall torque (oz-in / kg-cm) |
price |
| 5:1 Micro | 5:1 | 2450 | 50 mA | 360 mA | 1 / 0.1 | $15.95 |
| 10:1 Micro | 10:1 | 1250 | 40 mA | 360 mA | 2 / 0.2 | $15.95 |
| 30:1 Micro | 30:1 | 440 | 40 mA | 360 mA | 4 / 0.3 | $15.95 |
| 50:1 Micro | 50:1 | 250 | 40 mA | 360 mA | 6 / 0.4 | $15.95 |
| 100:1 Micro | 100:1 | 120 | 40 mA | 360 mA | 10 / 0.7 | $15.95 |
| 150:1 Micro | 150:1 | 85 | 40 mA | 360 mA | 15 / 1.1 | $15.95 |
| 210:1 Micro | 210:1 | 60 | 40 mA | 360 mA | 19 / 1.3 | $15.95 |
| 250:1 Micro | 250:1 | 50 | 30 mA | 360 mA | 22 / 1.6 | $15.95 |
| 298:1 Micro | 298:1 | 45 | 30 mA | 360 mA | 25 / 1.8 | $15.95 |
| 5:1 Micro HP | 5:1 | 6000 | 120 mA | 1600 mA | 2 / 0.1 | $15.95 |
| 10:1 Micro HP | 10:1 | 3000 | 120 mA | 1600 mA | 4 / 0.3 | $15.95 |
| 30:1 Micro HP | 30:1 | 1000 | 120 mA | 1600 mA | 8 / 0.6 | $15.95 |
| 50:1 Micro HP | 50:1 | 625 | 100 mA | 1600 mA | 15 / 1.0 | $15.95 |
| 100:1 Micro HP | 100:1 | 315 | 80 mA | 1600 mA | 25 / 1.8 | $15.95 |
| 150:1 Micro HP | 150:1 | 200 | 70 mA | 1600 mA | 45 / 3.2 | $15.95 |
| 210:1 Micro HP | 210:1 | 140 | 70 mA | 1600 mA | 65 / 4.7 | $15.95 |
| 250:1 Micro HP | 250:1 | 120 | 70 mA | 1600 mA | 75 / 5.4 | $15.95 |
| 298:1 Micro HP | 298:1 | 100 | 70 mA | 1600 mA | 90 / 6.5 | $15.95 |
| 24:1 Mini | 24:1 | 410 | 70 mA | 420 mA | 4 / 0.3 | $14.95 |
| 100:1 Mini | 100:1 | 140 | 90 mA | 800 mA | 15 / 1.0 | $17.95 |
| 35:1 Mini | 35:1 | 350 | 70 mA | 1500 mA | 35 / 2.5 | $17.95 |
| 25:1 20Dx44L mm | 25:1 | 500 | 160 mA | 3300 mA | 20 / 1.5 | $19.95 |
| 19:1 37Dx52L mm | 19:1 | 250 | 170 mA | 2500 mA | 40 / 2.9 | $24.95 |
Note: These gearmotors do not come with mounting hardware, instructions, or packaging. The brass faceplate has two mounting holes threaded for 1.7 (dia) x 0.35 (mm/thd) x 4mm long screws (M1.7 × 4 mm), and our micro metal gearmotor bracket (sold separately) gives you even more mounting options.
