Put simply, a CNC machine is a computer-controlled device that manipulates the sort of manufacturing tools that you would find in many factories and other industrial settings. In the past, numerical control (NC) machines used systems like punched tape to send instructions to motors and servos which, in turn, controlled machines.

A typical example might have been the 1950s punched tape system which gave the instructions for where a drill bit would be automatically applied to a workpiece. Throughout the 1970s and 1980s, computers began to take over and replace these analogue systems. This led to computer numerical control (CNC) which are the sort of machines you can see today being used all over the globe.

Programmable Software for Machining

With a modern CNC machine, software is programmed which gives the machine its instructions. Instead of needing to load a new punched tape every time a design changes, with contemporary computer-aided design (CAD) software all that is needed is for the various dimensions of a workpiece to be entered digitally and the CNC machine can get to work to produce it. Most CNC machines work with a language that many of them share, known as G code.

A unified language helps to do away with errors that might occur due to multiple machines being used to create the same component, for example. Because of this ease of programming, CNC machines are able to be set up rapidly for one-off pieces of work or protracted runs of thousands. You can think of a CNC machine a computer-controlled robot that performs a very specific set of machining functions. 

Types of CNC Machines

One of the most common types of CNC machines around are designed for laser cutting. CAD-produced designs can often go straight into a CNC laser cutting device to shape anything from card to sheet metal in a very uniform fashion. Laser cut components are used in anything from packaging to high-precision aerospace components.

Electric discharge CNC machines are used in many manufacturing industries to shape workpieces by using sparks. Basically, the machine's programming will move its electrodes into just the right position to erode sections of material where they are unwanted. This process is also called CNC spark eroding.

CNC lathes are now commonplace, too. These have all but replaced manually controlled lathes in many factories. CNC lathes cut into revolving workpieces to shape them across one or more axes.