Gears on a center lathe

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The headstock of a centre lathe can be opened, revealing an arrangement of gears. These gears are sometimes replaced to alter the speed of rotation of the chuck. The lathe must be switched off before opening, although the motor should automatically cut off if the door is opened while the machine is running (a safety feature).

The speed of rotation of the chuck is usually set by using the gear levers. These are usually on top of the headstock or along the front and allow for a wide range of speeds.

However, sometimes the only way to set the lathe to a particular speed is to change the gear arrangement inside the headstock. Most machines will have a number of alterative gear wheels for this purpose.

* http://www.technologystudent.com/equip1/mlathe1.htmThere are many variants of lathes within the metalworking field. Some variations are not all that obvious, and others are more a niche area. For example, a centering lathe is a dual head machine where the work remains fixed and the heads move towards the workpiece and machine a center drill hole into each end. The resulting workpiece may then be used "between centers" in another operation. The usage of the term metal lathe may also be considered somewhat outdated these days, plastics and other composite materials are in wide use and with appropriate modifications, the same principles and techniques may be applied to their machining as that used for metal.

* http://en.wikipedia.org/wiki/Metal_lathe