The Engine Lathe

Lathe Operations - The Engine Lathe

The engine lathe operates on the principle of work being rotated against a cutting tool (Figure 1).

Figure 1 In turning, the cutting tool is fed into the revolving workpiece.

The term "engine lathe" can be traced back to the manner in which early metal cutting lathes were powered. These early lathes used steam engines to power the machine tool. Usually, a single steam engine was used to power many machines at the same time through a series of belts and pulleys. Today, all engine lathes use a single electric motor to provide the power to operate the machine.

The lathe is one of the oldest and most important machines in the machine shop (Figure 2).

Figure 2 Engine lathe

Lathe Operations

Engine lathes are capable of many different machining operations. Turning cylindrical surfaces, facing flat surfaces, cutting threads, drilling, and boring are some of the typical operations that are done on the engine lathe.


		Figure 3 Typical machining operations performed on the engine lathe

Lathe Size

The size of the lathe is determined by the swing and by the length of the bed. The swing indicates the largest diameter that can be turned over the bed ways (the flat or v-shaped bearing surfaces that align the machine). The bed length is not the same as the longest workpiece that can be turned. As you can see from Figure 4, the longest piece that can be turned is equal to the length of the bed minus the space taken up by the headstock and tailstock.

"A" is the length of the bed. "B" is the distance between centers. "C" is the swing.

Figure 4 The size of the lathe is determined by the "swing" and the length of the "bed."