What is a CNC machine?

A CNC or Computer Numerical Control machine is an electro mechanical machine that manipulates machine shop tools using computer generated programming. The instructions for the machine are in the form of computer generated drawings which are split up in to tool paths of differing thickness, depth and shape. There are many many different computer software packages upon which drawings can be created but only certain software packages that 'speak' tool paths, and this is the language the CNC machine understands. CNC machines come in a wide variety of sizes too, from small desktop size machines to the largest machine in the world which boasts a 15 foot x 35 foot bed and belongs to Thermwood, an American company who themselves manufacture CNC machines! However this size machine is not available on the market, they built it for themselves.

CNC machines have actually been around for longer than one might think, a gentleman by the name of John T. Parsons is credited with inventing the very first CNC machine whilst working for his father's company in the 1940s, he was working on helicopter rotary blades. This first version of CNC cutting required a three man team, one machinist would call out x and y co-ordinates to two other machinists who would make the appropriate cuts. This was then developed further with the help of MIT researchers, using punch cards with huge numbers of points which allowed for accurate and fully automated cutting. 

The ability to control workshop machine processes using computer programming makes a workshop more efficient and more accurate. Machine cuts will be made with greater speed, accuracy and consistency, so it has benefited countless industries since its inception 80 years ago in its many constantly evolving forms.