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.
Nottingham (/ˈnɒtɪŋəm/ (About this soundlisten) NOT-ing-əm) is a city and unitary authority area in Nottinghamshire, England. Part of the East Midlands region, it is 128 miles (206 km) north of London and 45 miles (72 km) northeast of Birmingham. To the west lies Derby, separated by the M1 motorway.
Nottingham has links to the legend of Robin Hood and to the lace-making, bicycle (notably Raleigh bikes) and tobacco industries. It was granted its city charter in 1897, as part of Queen Victoria's Diamond Jubilee celebrations. Nottingham is a tourist destination; in 2018, the city received the second highest amount of overnight visitors in the Midlands and the highest amount in the East Midlands.
In 2017, Nottingham had an estimated population of 329,200. The population of the city proper, compared to its regional counterparts, has been attributed to its historical and tightly-drawn city boundaries. The wider conurbation, which includes many of the city's suburbs, has a population of 768,638. It is the largest urban area in the East Midlands and the second-largest in the Midlands. Its Functional Urban Area, also the largest in the East Midlands, has a population of 919,484. The population of the Nottingham/Derby metropolitan area is estimated to be 1,610,000.
Its metropolitan economy is the seventh largest in the United Kingdom with a GDP of $50.9bn (2014). The city was the first in the East Midlands to be ranked as a sufficiency-level world city by the Globalization and World Cities Research Network.
Nottingham's public transport system won awards prior to 2015, including the largest publicly owned bus network in England, and is also served by Nottingham railway station and the modern Nottingham Express Transit tram system.
It is also a major sporting centre and, in October 2015, was named 'Home of English Sport'. The National Ice Centre, Holme Pierrepont National Watersports Centre and Trent Bridge international cricket ground are all based in or around the city, which is also the home of two professional football teams; the former world's oldest professional league club Notts County and Nottingham Forest, famously two-time winners of the UEFA European Cup under Brian Clough and Peter Taylor in 1979 and 1980. The city also has professional rugby, ice hockey and cricket teams, and the Aegon Nottingham Open, an international tennis tournament on the ATP and WTA tours. This accolade came just over a year after Nottingham was named as the UK's first City of Football.
On 11 December 2015, Nottingham was named a "City of Literature" by UNESCO, joining Dublin, Edinburgh, Melbourne and Prague as one of only a handful in the world. The title reflects Nottingham's literary heritage, with Lord Byron, D. H. Lawrence and Alan Sillitoe having links to the city, as well as a contemporary literary community, a publishing industry and a poetry scene.
The city is served by three universities: the University of Nottingham, Nottingham Trent University and the University of Law; hosting the highest concentration of higher education providers in the East Midlands.