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#REDIRECT [[Computer numerical control]]
{{nofootnotes|date=October 2008}}
:'''''CNC''' redirects here. For other uses, see [[CNC (disambiguation)]].''
[[Image:Small CNC Turning Center.jpg|thumb|A CNC Turning Center]]
[[Image:CNC panel Sinumerik.jpg|thumb|CNC panel [[Siemens]] Sinumerik]]
[[Image:CNC panel.jpg|thumb|upright|Siemens CNC panel]]
<!-- Unsourced image removed: [[Image:Nichols-ducati-part.jpg|thumb|CNC product|{{Typical CNC tool enclosure|1=Thursday, 14 February 2008}}]] -->
'''Computer numerical control''' ('''CNC''') is a computer "controller" that reads [[G-code]] and M-code commands and drives a [[machine tool]], a powered mechanical device typically used to fabricate components by the selective removal of material. CNC numerically interpolates the points along a cutting tool's toolpath and directs the [[servomechanism]]s that translate the data into movement. The operating parameters of the CNC can be altered via the Master Control Unit (MCU) of the machine.
==Historical overview==
CNC was preceded by [[numerical control|numerically controlled]] (NC) machines, which were hard-wired and their operating parameters could not be changed. NC was developed in the late 1940s and early 1950s by John T. Parsons in collaboration with the [[MIT]] Servomechanisms Laboratory. The first CNC systems used NC style hardware, and the computer was used for the tool compensation calculations and sometimes for editing.
Punched tape continued to be used as a medium for transferring G-codes into the controller for many decades after 1950, until it was eventually superseded by [[RS232|RS232 cables]], floppy disks, and now is commonly tied directly into [[Computer network|plant networks]]. The files containing the G-codes to be interpreted by the controller are usually saved under the .NC extension. Most shops have their own saving format that matches their [[International Organization for Standardization|ISO]] certification requirements.
The introduction of CNC machines radically changed the manufacturing industry. Curves are as easy to cut as straight lines, complex 3-D structures are relatively easy to produce, and the number of machining steps that required human action have been dramatically reduced.
With the increased automation of manufacturing processes with CNC machining, considerable improvements in consistency and quality have been achieved with no strain on the operator. CNC automation reduced the frequency of errors and provided CNC operators with time to perform additional tasks. CNC automation also allows for more flexibility in the way parts are held in the manufacturing process and the time required to change the machine to produce different components.
== Production environment ==
A series of CNC machines may be combined into one station, commonly called a "cell", to progressively machine a part requiring several operations. CNC machines today are controlled directly from files created by [[Computer-aided manufacturing|CAM]] software packages, so that a part or assembly can go directly from design to manufacturing without the need of producing a drafted paper drawing of the manufactured component. In a sense, the CNC machines represent a special segment of industrial robot systems, as they are programmable to perform many kinds of machining operations (within their designed physical limits, like other robotic systems). CNC machines can run over night and over weekends without operator intervention. Error detection features have been developed, giving CNC machines the ability to call the operator's mobile phone if it detects that a tool has broken. While the machine is awaiting replacement on the tool, it would run other parts it is already loaded with up to that tool and wait for the operator. The ever changing intelligence of CNC controllers has dramatically increased job shop cell production. Some machines might even make 1000 parts on a weekend with no operator, checking each part with lasers and sensors.
== Types of instruction ==
Poo
==Tools with CNC variants==
* [[Drill]]s
* [[Electrical discharge machining|EDM]]s
* [[Lathe (tool)|Lathe]]s
* [[Milling machine]]s
* [[CNC wood router|Wood router]]s
* [[Sheet metal|Sheet metal work]]s(Turret Punch)
* Wire bending machines
* [[Hot-wire foam cutter]]s
* [[Plasma cutting]]s
* [[Water jet cutter]]s
* [[Laser cutting]]
* [[Oxy-fuel welding and cutting|Oxy-fuel]]
* [[Surface grinder]]s
* [[Cylindrical grinder]]s
==See also==
*[[Computer-aided design]] (CAD)
*[[Computer-aided engineering]] (CAE)
*[[Computer-aided manufacturing]] (CAM)
*[[G-code]]
*[[STEP-NC]]
*[[Numerical control]]
*[[Machine tool]]
*[[Tooling University]] (offers online CNC training classes)
*[[Coordinate-measuring machine]] (CMM)
*[[Robert C. Byrd Institute]] CNC training and education.
*[[Direct Numerical Control]] DNC
*[[Configurable Network Computing]] JDEdwards CNC Administrator
*[[intelitek]] Developers of Educational CNC systems
*[[F1 In Schools]] F1 in Schools Technology Challenge
*[[Design_for_Manufacturability_for_CNC_machining]]
*[[Multi Spindle CnC Machines]]
== References ==
{{Unreferenced|date=October 2008}}
==External links==
{{commonscat}}
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*[http://www.linuxcnc.org The Enhanced Machine Controller], opensource CNC control software
*[http://mync.sourceforge.net MyNC Numerical Control System], opensource CNC software
{{Metalworking - CNC, CAD, and CAM}}
[[Category:Automation]]
[[Category:CNC, CAD, and CAM]]
[[Category:Embedded systems]]
[[Category:Machine tools]]
[[Category:Production and manufacturing]]
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