Gear hobbing is a technique that is used to create gear teeth configurations that are ideal for use in a wide range of machinery components. In cases where this takes place in a mass producing environment, it is accomplished through the use of precision machines that ensure that the cut of each tooth on each gear produced meets the specifications set by the producer.
Generally, a gear hobbing machine will make use of a series of customized bits that help to create the specific types of cutting and shaping necessary to create gears that posses exactly the right pitch and circle to work in various types of equipment. A customized bit is used for a particular size and type of gear, which helps to ensure that the cuts that are made into the blank surface of the circle of metal are relatively smooth and uniform.
Precision cutters guide the bits, with most of the more sophisticated machinery being driven by computer software rather than by the eye and hand of a human being. The exacting nature of the cuts made into the gear surface helps to ensure that the ratio of the pitch, depth, and angle of the teeth are uniform and will work perfectly when installed in the machines requiring that size and type of gear.
Custom gear hobbing is still pursued in many cultures around the world. Essentially, the creation of custom gears will involve tools and bits that are used to fashion the basic gear form, and then to slowly and meticulously form each of the teeth on the gear. Often, this also requires the artist to have access to the machine that will eventually house the gears, so the fit of teeth can be tested from time to time, ensuring an acceptable fit. Work of this type may involve materials such as hardwood. Typically, this manual process produces gears that are created for simpler types of machines that are not motor driven.
Gear hobbing is a trade that has been around for thousands of years, and has benefited humankind in a number of ways. As technology continues to advance, new methods of producing gears faster and more efficiently will likely advance the art, resulting in even more precise gear configurations.