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.
Great Yarmouth, often called Yarmouth, is a seaside resort and minster town in Norfolk, England, straddling the River Yare, some 20 miles (30 km) east of Norwich. A population of 38,693 in the 2011 Census made it Norfolk's third most populous place. Its fishing industry, mainly for herring, fell steeply after the mid-20th century and has all but vanished. North Sea oil from the 1960s brought an oil-rig supply industry that now services offshore natural gas rigs. More recent offshore wind power and other renewable energy have created further support services. Yarmouth has been a seaside resort since 1760 and a gateway from the Norfolk Broads to the North Sea. Tourism was boosted when a railway opened in 1844, which gave visitors easier, cheaper access and triggered some settlement. Wellington Pier opened in 1854 and Britannia Pier in 1858. Through the 20th century, Yarmouth was a booming resort, with a promenade, pubs, trams, fish-and-chip shops and theatres, and the Pleasure Beach, the Sea Life Centre, the Hippodrome Circus and the Time and Tide Museum, and a surviving Victorian seaside Winter Garden in cast iron and glass.