What Is an Automatic Lathe, How Does It Work?

What Is an Automatic Lathe?

Automatic lathes are industrial machines that use a mechanical system to machine cylindrical parts in series through a set cycle. These lathes use cam profiles to control the motions, and these motions repeat cyclically.

Cam-based automatic lathes are used for regular, repeating operations, such as shaping, cutting, knurling, drilling, reaming, and thread cutting. These help provide very high efficiency and accuracy and are usually easy to find at a low cost. CNC and pneumatic automatic lathes also exist.

Cam Control

Classic automatic lathes are controlled by mechanical cams that synchronize the tool motions.

Swiss-Type Automatic Lathe

Swiss-type automatic lathes pass the material through a guide bushing, allowing precise machining of long, thin parts.

Production Speed

Automatic lathes can produce hundreds of small parts per hour by running continuously without human intervention.

How Does an Automatic Lathe Work?

This machine uses cam profiles to control motions and automatically carries out repetitive operations. The cam profiles define a specific sequence and speed of motions required for each cycle. Cam-based automatic lathes are used for operations such as cutting, machining, drilling, and thread cutting on cylindrical parts.

Take a look at how the cam-mechanism toy in the video works. The movements of the cat and mouse are created by cams and followers that track the cams’ motion, transmitting that motion.

Automatic lathes operate with a very similar system. We can compare the motions of the tool holders in an automatic lathe to the movements of the cat and mouse. With one small difference: in automatic lathes, the motion of the cams is driven by an electric motor.

A toy with a cam mechanism

Working Principle of an Automatic Lathe

Programming: A specific sequence and speed of operations is defined, either through a CNC system or through manual programming.
Cam loading: The cam profile is loaded and positioned on the lathe.
Starting: The lathe begins carrying out the programmed operations.
Cam motion: The cam profile makes the motions required to complete the operation and controls the lathe tools.
Completion of the operation: Once the cam motion is complete, the lathe stops automatically and the results of the operation can be examined.

Cam-based automatic lathes provide efficiency and accuracy for repetitive operations and help businesses shorten their production times.

Features of Automatic Lathes

The surface roughness of the machined part, for example for copper material, can be as low as Ra0.04-0.08.
The feed mechanism automatically feeds the bar stock.
The process requires no manual inspection and provides a fully automatic production process.
An operator can run multiple machines at the same time.

Each rotation of the cam completes the machining of one part. Cam speed is 1.0~36 rpm, adjustable according to different workpieces, and the fastest operation is 36 parts per minute.

Since five cutting tools can operate at the same time, machining efficiency is very high. Because five tools on the tool post and two tailstock spindles can work simultaneously during the machining process, automatic lathes can machine parts 4-6 times faster than CNC lathes.