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.
Grimsby, also Great Grimsby, is a large coastal English seaport and administrative centre in North East Lincolnshire, on the South Bank of the Humber Estuary, close to where it reaches the North Sea. It was the home port for the world's largest fishing fleet by the mid-20th century, but fishing fell sharply after the Cod Wars denied the United Kingdom access to Icelandic fishing grounds, and the European Union parcelled out fishing quotas in waters within a 200-nautical-mile (370 km) limit of the UK coast to other European countries, in line with its Common Fisheries Policy. Grimsby has since suffered post-industrial decline, although food production has spread since the 1990s. The Grimsby–Cleethorpes conurbation acts as a cultural and economic centre for much of north and east Lincolnshire. Grimsby people are called Grimbarians; the term codhead is also used jokingly, often for Grimsby football supporters. Great Grimsby Day is 22 January.