# Gears

Gears are toothed mechanical components that transmit motion and force between rotating shafts. They are crucial in controlling speed, torque, and direction in machines by interlocking and transferring energy efficiently.

In *FIRST Tech Challenge*, gears are essential for designing and optimizing robot mechanisms. They help teams build drivetrains, arms, and manipulators that can move with precision and efficiency. By selecting the right [gear ratios](/transmitting-power/gears/gear-ratios.md), teams can balance speed and torque to improve their robot’s performance in competition. 

Gears come in many distinct shapes, each suited for different mechanical functions:

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{% tab title="Common Gears in FTC" %}

| <p><strong>Spur Gear</strong></p><p>These are the most common types of gears used in FTC. The teeth are parallel to the axis of rotation. Spur gears can only be used on parallel shafts.</p> | <div><figure><img src="/files/5wUgwgSZKDaIti3vIxsH" alt=""><figcaption><p><em>13302 MKA Robotics wrist mechanism</em></p></figcaption></figure></div> |
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| <p></p><div><figure><img src="/files/WkTm8KRLFmbcxcd5xwyW" alt=""><figcaption><p><em>17670 Raider Robotics Outake wrist</em></p></figcaption></figure></div> | <p><strong>Helical Gear</strong></p><p>Teeth are twisted obliquely to the gear axis.</p> |
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| <p><strong>Bevel Gear</strong></p><p>One of a pair of gears used to connect two shafts whose axes intersect, and the pitch surfaces are cones. Teeth are cut along the pitch cone. </p> | <p></p><div><figure><img src="/files/IGDy5yZb6TRJBNbUWZVr" alt=""><figcaption><p><em>19823 Jolly Blue's Differential Swerve drive</em></p></figcaption></figure></div> |

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| <p></p><div><figure><img src="/files/z7Tr14RLiPHVLaHPI89g" alt=""><figcaption><p><em>17670 Raider Robotics Power Take-Off</em></p></figcaption></figure></div> | <p><strong>Miter Gear</strong></p><p>A special class of bevel gear where the shafts intersect at 90° and the gear ratio is 1:1.</p> |
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{% tab title="Uncommon Gears in FTC" %}

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| <p><strong>Rack</strong></p><p>The rack is a bar containing teeth on one face for meshing with a gear.</p> | ![](https://lh7-rt.googleusercontent.com/docsz/AD_4nXdZh4ailAFDYq6o4AecoeOsnE7zJOzeOm9nNDQfuzQTUZJ8n3GmVMOLok9e4jGWTZ2mdeTREKq4sM88f1hJWQ3mWjck8uwxxogAeouuOszqXiKDM4PdvGEKeZ6Sw4qNJaw5glgAYA?key=l78xoyVWhVq4XRDwJujbd3mS) |

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| <p><strong>Internal Gear</strong></p><p>An annular gear has teeth on the inner surface of its rim.</p><p>The internal gear always meshes with the external gear.</p> | ![](https://lh7-rt.googleusercontent.com/docsz/AD_4nXcNNgQXehJVOxyPny1bp3H-sjU8eKvBBTnaqmhcf-05w93Gi7JzFguknJ0Fr-v5OYK7vtnoPKNf5nyRBNNoRSDldAjZBW2bq0LxdpSWQOSAYecBbWStJpKoOryoLrGGkEGfMrGW?key=l78xoyVWhVq4XRDwJujbd3mS) |

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| <p><strong>Screw Gear</strong></p><p>A helical gear that transmits power from one shaft to another, non-parallel,</p><p>non-intersecting shafts.</p> | ![](https://lh7-rt.googleusercontent.com/docsz/AD_4nXd1asq1Rksy7kM9IMSDIjaoyjPvlSDL3ad2q-tqVyvpvw82Z4pkJTnNZ8fKYXFFXaFjOFdOV1yxss74sl9DR499TeyD-SI5a_brIbNABVRb8Sep8NY5yp74mXE72l6XBm_0YVBrdg?key=l78xoyVWhVq4XRDwJujbd3mS) |

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| <p><strong>Worm Gear</strong></p><p>The worm is a shank having at least one complete tooth (thread) around the pitch surface; the driver of a worm wheel. A worm wheel is a gear with teeth cut on an angle to be driven by a worm.</p> | ![](https://lh7-rt.googleusercontent.com/docsz/AD_4nXd3LSBqKoxr4O66tzu_IQXdWhtVjwtD7STT86yZWxcnbMBeWi6crlw-Hqvr6NeHFujNvqfm35t-dkh3tan7X80Zen2ahSuE6BJg6J0pezpec6HCt7kWTteCn-UURuV4zSQb2ITghQ?key=l78xoyVWhVq4XRDwJujbd3mS) |

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