Computer Numerical Control (CNC)
Numerical control (also computer numerical control, and commonly called CNC) is the automated control of machining tools (such as drills, lathes, mills and 3D printers) by means of a computer. A CNC machine processes a piece of material (metal, plastic, wood, ceramic, or composite) to meet specifications by following a coded programmed instruction and without a manual operator directly controlling the machining operation.
A CNC machine is a motorized maneuverable tool and often a motorized maneuverable platform, which are both controlled by a computer, according to specific input instructions. Instructions are delivered to a CNC machine in the form of a sequential program of machine control instructions such as G-code and M-code, then executed. The program can be written by a person or, far more often, generated by graphical computer-aided design (CAD) or computer-aided manufacturing (CAM) software. In the case of 3D printers, the part to be printed is "sliced", before the instructions (or the program) is generated. 3D printers also use G-Code.
CNC is a vast improvement over non-computerized machining that must be manually controlled (e.g. using devices such as hand wheels or levers) or mechanically controlled by pre-fabricated pattern guides (cams). In modern CNC systems, the design of a mechanical part and its manufacturing program is highly automated. The part's mechanical dimensions are defined using CAD software and then translated into manufacturing directives by computer-aided manufacturing (CAM) software. The resulting directives are transformed (by "post processor" software) into the specific commands necessary for a particular machine to produce the component and then are loaded into the CNC machine.
Since any particular component might require the use of a number of different tools – drills, saws, etc. – modern machines often combine multiple tools into a single "cell". In other installations, a number of different machines are used with an external controller and human or robotic operators that move the component from machine to machine. In either case, the series of steps needed to produce any part is highly automated and produces a part that closely matches the original CAD drawing.
Buxton is a spa town in Derbyshire, in the East Midlands region of England. It has the highest elevation – about 1,000 feet (300 m) above sea level – of any market town in England.[nb 1] Close to the county boundary with Cheshire to the west and Staffordshire to the south, Buxton is described as "the gateway to the Peak District National Park". A municipal borough until 1974, Buxton was then merged with other localities lying primarily to the north, including Glossop, to form the local government district and borough of High Peak within the county of Derbyshire. It is also near to Greater Manchester. The population of the town was 22,115 at the 2011 Census.
Buxton landmarks include Poole's Cavern, an extensive limestone cavern open to the public, and St Ann's Well, fed by the geothermal spring bottled and sold internationally by Buxton Mineral Water Company. Also in the town is the Buxton Opera House, which hosts several music and theatre festivals each year. The Devonshire Campus of the University of Derby is housed in one of the town's historic buildings.
Buxton is twinned with two towns: Oignies in France and Bad Nauheim in Germany.