Gear Ratios

A gear ratio is the relationship between the sizes of two gears. If a smaller driving gear turns a larger driven gear, the larger gear rotates more slowly but with greater torque.

For example, if a driving gear has 10 teeth and the driven gear has 20 teeth, the ratio is 2:1, meaning the smaller gear must complete two full rotations for the larger gear to rotate once.

A diagram of a 2:1 Gear ratio by Bartosz Ciechanowski

Gear ratios in FIRST Tech Challenge are crucial for optimizing speed and torque, depending on the task at hand.

Increasing Speed

If you use a higher gear ratio (2:1, for example), the output gear spins faster than the input gear, while lowering torque. This is particularly useful for applications such as active intake, flywheel, or turret systems.

Increasing Torque

A lower gear ratio (1:2, for example) means the output gear rotates more slowly but with greater force. This is ideal for lifting mechanisms, drivetrains, or linear extension.

To optimize efficiency, ensure that torque and speed are balanced; having excess torque on a wrist joint could mean wasted force, so gearing it up for extra speed can improve movement while maintaining control. Always match the gear ratio to the actual load and motion requirements to avoid inefficiencies that drain power or limit performance.