A gearbox lathe is a type of lathe that is equipped with a gearbox that allows the operator to change the speed of the spindle while machining a workpiece. The gearbox is typically located on the headstock of the lathe and is operated by a lever or a set of levers.

The purpose of the gearbox is to provide a wide range of spindle speeds that can be adjusted to suit the requirements of the workpiece being machined. The gearbox contains a set of gears that can be engaged or disengaged to change the speed of the spindle. The gears are arranged in a series of ratios that allow the to be changed in discrete steps.

The gearbox lathe is commonly used in the manufacturing industry for a wide range of applications, including turning, facing, drilling, reaming, and threading. The ability to change the spindle speed quickly and easily enables the operator to produce accurate and consistent results, even when machining
When designing a gearbox lathe, several factors must be taken into consideration, including the size and weight of the workpiece, the material being machined, and the accuracy required of the finished product. The gearbox must be designed to provide a range of speeds that can handle a variety of machining tasks, from roughing to finishing.

In addition to the gearbox, a lathe may also be equipped with other features such as a digital readout (DRO), and a tailstock. The DRO provides the operator with a digital display of the position of the unit which helps to ensure accuracy and consistency. The tool post is used to hold the cutting tools, while the tailstock is used to support the workpiece during machining.

Overall, the gearbox lathe is a versatile and essential tool for the manufacturing industry, providing the operator with the ability to change spindle speeds quickly and easily, resulting in accurate and consistent results.