What Is CNC Machining?

CNC machining is a manufacturing process in which pre-programmed computer software dictates the movement of factory tools and machinery. The process can be used to control a range of complex machinery, from grinders and lathes to mills and routers. With CNC machining, three-dimensional cutting tasks can be accomplished in a single set of prompts.

Short for “computer numerical control,” the CNC process runs in contrast to — and thereby supersedes — the limitations of manual control, where live operators are needed to prompt and guide the commands of machining tools via levers, buttons and wheels. To the onlooker, a CNC system might resemble a regular set of computer components, but the software programs and consoles employed in CNC machining distinguish it from all other forms of computation.

When a CNC system is activated, the desired cuts are programmed into the software and dictated to corresponding tools and machinery, which carry out the dimensional tasks as specified, much like a robot.

In CNC programming, the code generator within the numerical system will often assume mechanisms are flawless, despite the possibility of errors, which is greater whenever a CNC machine is directed to cut in more than one direction simultaneously. The placement of a tool in a numerical control system is outlined by a series of inputs known as the part program.

With a numerical control machine, programs are inputted via punch cards. By contrast, the programs for CNC machines are fed to computers though small keyboards. CNC programming is retained in a computer’s memory. The code itself is written and edited by programmers. Therefore, CNC systems offer far more expansive computational capacity. Best of all, CNC systems are by no means static, since newer prompts can be added to pre-existing programs through revised code.

In CNC, machines are operated via numerical control, wherein a software program is designated to control an object. The language behind CNC machining is alternately referred to as G-code, and it’s written to control the various behaviors of a corresponding machine, such as the speed, feed rate and coordination.

Basically, CNC machining makes it possible to pre-program the speed and position of machine tool functions and run them via software in repetitive, predictable cycles, all with little involvement from human operators. Due to these capabilities, the process has been adopted across all corners of the manufacturing sector and is especially vital in the areas of metal and plastic production.

For starters, a 2D or 3D CAD drawing is conceived, which is then translated to computer code for the CNC system to execute. After the program is inputted, the operator gives it a trial run to ensure no mistakes are present in the coding.

In today’s CNC protocols, the production of parts via pre-programmed software is mostly automated. The dimensions for a given part are set into place with computer-aided design (CAD) software and then converted into an actual finished product with computer-aided manufacturing (CAM) software.

Any given work piece could necessitate a variety of machine tools, such as drills and cutters. In order to accommodate these needs, many of today’s machines combine several different functions into one cell. Alternately, an installation might consist of several machines and a set of robotic hands that transfer parts from one application to another, but with everything controlled by the same program. Regardless of the setup, the CNC process allows for consistency in parts production that would be difficult, if not impossible, to replicate manually.