CNC machining software is an operator’s program interface for controlling industrial fabrication machinery. CNC is the abbreviation for “computer numerical control.” A machine is uploaded with instructions on how to fabricate a product based on its precise but purely numeric description.
With the invention of solid state electronics and the era of exponential miniaturization it ushered, starting around 1950, component parts of commercial products required correspondingly small tolerances in precision. It was far too cumbersome to control the machinery to fabricate such detailed components manually with levers and cams. The first numerically controlled machines read a paper tape punched with holes encoded to represent their spatial positioning and to control with servo motors their precise movement.
Modern CNC machining, which has revolutionized large scale manufacturing, remains essentially the same in principle. The instructions that control a machine are stored on a computer’s spinning magnetic hard drive or static digital flash drives. The fundamental operation of most machines have not changed, and therefore, the set of instructions has not either. The most significant changes have occurred in the CNC machining software.
There are many types of CNC machines. One of the most common are lathes. A block of material such as wood or metal is either held stationary or precisely moved, as in the case of the axial spinning of a turning lathe. It is formed with the subtraction of material by a task-specific, sharp drill bit at high revolution moving along the contour of the desired shape. The critical function of CNC machining software is to map, or model, this three dimensional shape into its x-y-z Cartesian axis coordinates.
The term computer numerical control machining is an accurate one. A lathe is first calibrated to its target’s 0-0-0 coordinates, and its drilling advances to the next assigned set of numbered coordinates, and the next, according to its mapped instructions. In nascent times, this was the literal method. Machines were input with a linear sequence of a set of three numbers, all typed with a numeric keypad according to a design engineer’s calculations and measurements.
Nearly all modern CNC machining software is custom integrated with the specific machine; each has its own mechanical specifications and thus cannot be controlled well with any generic, retail, or open source code. With increase in electronic hardware’s processing power, CNC machining computer programs have become more powerful and user-friendly. Computers are now capable of translating analog vectors and curves that define most shapes into digital numbers, and graphic user interfaces like CAD — computer aided design — have been incorporated into CNC machining software.
CNC machines were created so that an operator could simply press buttons to start, end, and reset. Sophistication in software furthermore frees the craftsman to become a creative designer, simply drawing and automatically computerizing the drawing numerically and having a machine make it real. Advances in digital telecommunication have further revolutionized industrial manufacturing with the capacity to upload code to a machine thousands of miles away for single-run prototyping. New CNC home/garage machines are available with desktop footprints, including 3D printers that reverse a lathe’s purpose, depositing a reservoir of material such as plastic into a form defined by software, seemingly creating something from nothing.