Gear cutting is the process of creating a precise gear from a steel, or any other material, blank in order to coincide with the teeth of an opposing gear. Gear cutting is done through a number of methods, all with the same goal. The purpose or objective is to create a precisely timed gear, meaning the ratio of the gear creates the desired rotational speed. The gear must also be perfectly sized and able to be incorporated into a mechanical system as a means of transferring power from an energy source, such as a motor or drive shaft.
Gear cutting has evolved from a process in which a toothed radius was carved out of a piece of wood. Today, the process allows for a hardened steel alloy made to be cut by lasers to exact dimensions within .001 inch (0.00254 cm). The process of gear cutting has evolved to create gears that are able to withstand tremendous amounts of force and pressure.
Advances in gears have mainly come as a result of the use of stronger materials that make up the gear itself. The problem with these stronger materials is that the stronger the material used to create the gear, the harder it is to cut the gear out of the material. As such, there have been quite a few different methods of gear cutting developed over time to be used as efficient means of creating strong, durable gears.
These methods include everything from laser cutting to extrusion, since gears can be made out of virtually any material that lends itself to manipulation. For example, plastics can be extruded in precise shapes and sizes that are very hard and resilient to chemicals. Different metallurgical sciences have also created alloys that allow for hardened metals that are much lighter yet much stronger than that of ordinary steel, which is a very resilient material. Materials can also be cut from wood, which is mostly done today as a traditionalist or hobbyist method of gear cutting, such as in clock making.
When a gear has to be created with absolute precision, a laser that is guided by a computer is used to manufacture the gear to the specifications entered into the computer system. This precision machining method of cutting gears is generally used in high-performance engine parts. It can also be used in systems that require the utmost accuracy in their primary function.