This page collects information on various motors available that are suitable for robots. Some motors have a motor encoder kit available, to perform odometry.

So far we have experience with two motors: the OSEPP 25mm motor that comes with the OSEPP Tank Kit, and the micro gear motors (made by Pololu?). The latter are available in a variety of gear ratios. Both have a Hall Effect motor encoder kit available.

Note: Stalling or overloading gearmotors can greatly decrease their lifetimes and even result in immediate damage. The recommended upper limit for instantaneous torque is 2.5 kg-cm (35 oz-in) for the 380:1 and 1000:1 gearboxes, and 2 kg-cm (25 oz-in) for all the other gear ratios; we strongly advise keeping applied loads well under this limit. Stalls can also result in rapid (potentially on the order of seconds) thermal damage to the motor windings and brushes, especially for the versions that use high-power (HP and HPCB) motors; a general recommendation for brushed DC motor operation is 25% or less of the stall current. — source:  Pololu

Pololu Micro Gear Motors#

These tiny brushed DC gearmotors are available in a wide range of gear ratios—from 5:1 up to 1000:1—and with five different motors: high-power 6 V and 12 V motors with long-life carbon brushes (HPCB), and high-power (HP), medium power (MP), and low power (LP) 6 V motors with shorter-life precious metal brushes. The 6 V and 12 V HPCB motors offer the same performance at their respective nominal voltages, just with the 12 V motor drawing half the current of the 6 V motor. The 6 V HPCB and 6 V HP motors are identical except for their brushes, which only affect the lifetime of the motor.

OSEPP Motor#

This is the motor that comes with the OSEPP Tank Kit. You can buy motor kits that come with an anodised aluminium wheel, a silicon tire. A Hall Effect motor encoder kit is available separately.

• Voltage: 9v DC
• Length: 52mm
• Diameter: 25mm
• Rated Torque (Kgf.cm): 1.5
• RPM: 8500

MiniQ Motor Wheel Set#

RobotShop sell a MiniQ Motor Wheel Set w/ Encoder that includes two micro gear motors, wheels, white plastic hubs, and a motor encoder pair — with the encoders integrated into the motor mount — for US$36. They use a 50:1 gear ratio rather than 298:1 (perhaps that's better?). This uses an optical encoder rather than a Hall Effect encoder, using the white teeth of the inner wheel hub for the optical interrupter, 48 pulses per revolution.