The earliest numerical control machines date to the 1940s when motors were first employed to control the movement of pre-existing tools. As technologies advanced, the mechanisms were enhanced with analog computers, and ultimately with digital computers, leading to the rise of CNC machining.

The vast majority of today’s CNC arsenals are completely electronic. Some of the more common CNC-operated processes include ultrasonic welding, hole-punching and laser cutting. The most frequently used machines in CNC systems include the following:

CNC Mills

CNC mills are capable of running on programs comprised of number- and letter-based prompts that guide pieces across various distances. The programming employed for a mill machine could be based on either G-code or some unique language developed by a manufacturing team. Basic mills consist of a three-axis system (X, Y and Z), though most newer mills can accommodate three additional axes.

Lathes

In lathe machines, pieces are cut in a circular direction with indexable tools. With CNC technology, the cuts employed by lathes are carried out with precision and high velocity. CNC lathes are used to produce complex designs that wouldn’t be possible on manually run versions of the machine. Overall, the control functions of CNC-run mills and lathes are similar. As with CNC mills, lathes can be directed by G-code or unique proprietary code. However, most CNC lathes consist of two axes — X and Z.

Plasma Cutters

In a plasma cutter, a plasma torch cuts the material. The process is foremost applied to metal materials but can also be employed on other surfaces. In order to produce the speed and heat necessary to cut metal, plasma is generated through a combination of compressed-air gas and electrical arcs.

Electric Discharge Machines

Electric-discharge machining (EDM) — alternately referred to as die sinking and spark machining — is a process that molds workpieces into particular shapes with electrical sparks. With EDM, current discharges occur between two electrodes, and this removes sections of a given workpiece.

When the space between the electrodes becomes smaller, the electric field becomes more intense and thus stronger than the dielectric. This makes it possible for a current to pass between the two electrodes. Consequently, portions of a workpiece are removed by each electrode. Subtypes of EDM include:

• Wire EDM: Wire EDM uses spark erosion to remove portions from an electronically conductive material.

• Sinker EDM: Sinker EDM utilizes an electrode and workpiece soaked in dielectric fluid for the purpose of piece formation.

In a process known as flushing, debris from each finished workpiece is carried away by a liquid dielectric, which appears once the current between the two electrodes has stopped and is meant to eliminate any further electric charges.

Water Jet Cutters

In CNC machining, water jets are tools that cut hard materials, such as granite and metal, with high-pressure applications of water. In some cases, the water is mixed with sand or some other strong abrasive substance. Companies often shape factory machine parts through this process.

Water jets are employed as a cooler alternative for materials that are unable to bear the heat-intensive processes of other CNC machines. Due to their cooler nature, several sectors like the aerospace and mining industries rely on water jets, where they use them for carving and cutting, among other functions. Companies also use water jet cutters for applications requiring very intricate cuts in material, as the lack of heat prevents any change in the material’s intrinsic properties that may result from metal on metal cutting.