CNC Lathe and turning
CNC lathes are rapidly replacing the older production lathes (multispindle, etc) due to their ease of setting and operation. They are designed to
use modern carbide tooling and fully utilize modern processes. The part may be designed by the Computer-aided manufacturing (CAM) process, the resulting
file uploaded to the machine, and once set and trialled the machine will continue to turn out parts under the occasional supervision of an operator.
The machine is controlled electronically via a computer menu style interface, the program may be modified and displayed at the machine, along with a
simulated view of the process. The setter/operator needs a high level of skill to perform the process, however the knowledge base is broader compared
to the older production machines where intimate knowledge of each machine was considered essential. These machines are often set and operated by the
same person, where the operator will supervise a small number of machines (cell).
The design of a CNC lathe has evolved yet again however the basic principles and parts are still recognisable, the turret holds the tools and indexes
them as needed. The machines are totally enclosed, due in large part to Occupational health and safety (OH&S) issues.
With the advent of cheap computers, free operating systems such as Linux, and open source CNC software, the entry price of CNC machines has plummeted.
For example, Sherline makes a desktop CNC lathe that is affordable by hobbyists.
Most CNC Swiss style lathes today utilize two spindles. The main spindle is used with the guide bushing for the main machining operations.
The secondary spindle is located behind the part, aligned on the Z axis. In simple operation it picks up the part as it is cut off (or parted off) and
ejects it into a bin, eliminating the need to have an operator manually change each part, as is often the case with standard CNC turning centers.
This makes them very efficient, as these machines are capable of fast cycle times, producing simple parts in one operation in as little as 10-15 seconds. This makes them ideal for large production runs of small diameter parts.