CNC (computer numerical control) machines refers to a subtractive machining process where parts are produced by "cutting away" material from a block (also known as the workpiece or the blank). This is basically a completely different approach than additive (3D printing) and formative (Injection Molding) techniques. CNC machines, or Computer Numerically Controlled machining (CNC) machines, use high-end computer software and controls to create a machined part. Here are a few different types of CNC processes that are commonly used:
CNC cutting is an application where the machine's cutting-edge moves through a series of holes in a materialized work piece, cutting away material at a predetermined rate. This cutting edge can be made from many different materials. Common materials used in CNC cutting include plastics, ceramics, metals, and even paper.
CNC sanding is an abrasive cutting process that uses an abrasive or mechanical blade to remove material from the surface of a working materialized work piece. This abrasive is used to help with removing the surface material (such as oil or grease) that is embedded in the surface of the materialized work piece. Often times, these machines are also equipped with a high-pressure spray chamber for the purpose of achieving this effect.
Metal CNC grinding, which is often referred to as gas metal arc welding, is used to quickly create a smooth surface on either a threaded rod or a flat plate using a welding process. The process involves a hot surface (metal or another metal material) is passed over a rotating tool to heat it up and to create a spinning motion. This spinning motion causes the metal to create a thin surface, similar to sandpaper, which allows for a smooth surface finish when the metal is placed on the plate or threaded rod.
Laser CNC cutting is used for making a very precise, detailed cut, usually in line with a machine's cutting. There are two different types of laser CNC machinery, including a laser cutter and a laser engraver. {which uses laser light to etch a pattern onto the surface of a work piece. The laser engraver uses two laser beams, one to activate the ink and the other to illuminate the material, resulting in the creation of a pattern on the work piece.
One important process of CNC machining is TIG welding (tungsten inert gas). This procedure is used to fuse two pieces of metal together using inert gas in a controlled environment. The gases are usually ignited through a wire feed or by burning the metal, both of which are done by a controller, as the gas ignites by the heat of the heat source (usually the metal being fused).