When the going gets tough, the tough get gearmotors!

Adding a gear-train to the output of any motor will reduce the speed, while simultaneously increasing torque. Gearing can be added to any type of motor. There is no need to waste time designing a geartrain and sourcing all the parts. Chances are, there is a gearmotor solution that you can drop right into your design.

Gear train construction ranges from simple plastic drive-trains for toys to beefy metal gear-trains for extra-high-torque applications.
Gear trains can be mated to brushed or brushless DC motors as well as steppers. Gear-train modules in a variety of gear ratios are available to fit standard NEMA sized steppers.


  • Robot Drive Trains
  • Radio Control Vehicles
  • Cordless Tools


  • Speed Reduction - Many DC motors simply run too fast to be useful in direct-drive applications.
  • Increased Torque - A lot of work can be coaxed from a relatively small motor if fitted with a suitable gear train.


The potential downsides of adding a gear train to a motor include:
  • Friction - This is especially a problem with low-cost plastic gear trains used with low-voltage motors. The extra resistance can make these gear-trains balky at low speeds.
  • Inertia - This is more of a problem with metal gear-trains. All that additional rotating mass can inhibit rapid acceleration.
  • Backlash - Any sloppiness in the gear-train tolerances create slack that must be taken up whenever the direction reverses. This can be a problem in precision motion control applications.
High-end precision gear-trains can be optimized to minimize any or all of these disadvantages. But be prepared to pay a premium price for them!

This guide was first published on May 21, 2014. It was last updated on May 21, 2014.

This page (Geared Motors) was last updated on Apr 03, 2014.

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