---
title: Motors
---

A **motor**, in the context of the [FIRST Robotics Competition](first-robotics-competition), is a device that translates [electrical energy](http://www.wikipedia.org/wiki/Electricity "wikipedia:Electricity") into [mechanical energy](http://www.wikipedia.org/wiki/Mechanical_engergy "wikipedia:Mechanical_engergy"), which is most often output as [rotary motion](http://www.wikipedia.org/wiki/rotation "wikipedia:rotation") along a shaft.

Within the [kit of parts](kit-of-parts), [FIRST](first) provides each team with a number of such motors to be used in the construction and operation of their [robot](robot). Each motor features unique operating characteristics and behaviors that are governed by [physics](physics) and understanding such characteristics is important for a team to choose the correct, most efficient motor to accomplish a given task.

## Characteristics

For determining the efficacy of a motor in performing a certain task, there are certain values describing that motor that are necessary for performing some calculations.

- **Stall torque** is the maximum [torque](torque) value a given motor can produce. When a motor is said to have stalled, that indicates that its rotary motion has stopped, having reached equilibrium with its environment. Stalling a motor is not positive because of its effect on current draw. This is measured in units such as Newton_meter (N_m), inch_lbs (in_lbs.), etc.
- **Stall current** is the value of electrical current drawn by a motor in a stall condition. This value often exceeds the limits on [current](http://www.wikipedia.org/wiki/Electric_current "wikipedia:Electric_current") use imposed by [FIRST](first) and can result in damage to the motor and other electrical components. This is measured in units of amperage (A).
- **Free speed** is the highest speed at which the shaft rotates, measured when the force acting upon said shaft is as close to zero as possible. Zero force acting upon a shaft is impossible, however, due to environmental factors such as gravity and friction. Free speed is measured in revolutions per minute (RPM) or radians per second (rad/s).
- **Free current** is a measurement of the current drawn to the motor under a minimum load condition, previously defined as its 'free speed'. This is measured in units of amperage (A).

Data about motors previously provided to [FIRST Robotics Competition](FIRST_Robotics_Competition "FIRST Robotics
Competition") participant [teams](team) can be found at the individual motor pages.

## Motors

{% include by_tag collection=site.tech tag="motor" %}

## Obsolete Motors

{% include by_tag collection=site.tech tag="obsoletemotor" %}