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.
Newmarket is a market town in the English county of Suffolk, approximately 65 miles (105 kilometres) north of London. It is generally considered the birthplace and global centre of thoroughbred horse racing and a potential World Heritage Site. It is a major local business cluster, with annual investment rivalling that of the Cambridge Science Park, the other major cluster in the region. It is the largest racehorse training centre in Britain, the largest racehorse breeding centre in the country, home to most major British horseracing institutions, and a key global centre for horse health. Two Classic races, and an additional three British Champions Series races are held at Newmarket every year. The town has had close royal connections since the time of James I, who built a palace there, and was also a base for Charles I, Charles II, and most monarchs since. The current monarch, Queen Elizabeth II, visits the town often to see her horses in training.
Newmarket has over fifty horse training stables, two large racetracks, the Rowley Mile and the July Course, and one of the most extensive and prestigious horse training grounds in the world. The town is home to over 3,500 racehorses, and it is estimated that one in every three local jobs is related to horse racing. Palace House, the National Heritage Centre for Horseracing and Sporting Art, the National Horseracing Museum, Tattersalls racehorse auctioneers, and two of the world's foremost equine hospitals for horse health, are in the town, which is surrounded by over sixty horse breeding studs. On account of its leading position in the multibillion-pound horse racing and breeding industry, it is also a major export centre.