Computer Numerical Control or CNC:
Computer Numerical Control or CNC is the designation of a machine that runs from the instructions feed to it via a computer controller.

Robot While the average person may not be familiar with the term CNC, those working in the manufacturing industry today are likely exposed to it. CNC machines are used in a wide range of manufacturing processes.

They are used to saw, mill, drill, grind, polish, deburr, punch, press, bend, weld, measure, assemble, package, draw, print, engrave, sew, tape, cut, and glue. They are used to work in hazardous enviornments. They are also used to tend to other machines like a machine operator. The image on the right shows a CNC Robot Tending to a CNC Press.

CNC roots go back to the late 1940s. Later it was named NC for Numerical Control and the control received instructions from a pre-punched tape or card. In the 1960s a computer replaced the punched tape hence the designation Computer Numerical Control, or CNC. In the 1970s machine tool manufacturers were in full swing building machine tools with CNC controls.
The CNC Control or Controller:
Control The CNC Control is the CNC Machine's computer. For machine tools, the controller and other electronics are commonly built upon what was a conventional machine like a milling machine or lathe. This took the cranking of handles out of the picture. Complex profiled and contoured parts are now very precisely machined in a much shorter timeframe.
The CNC Axis:
A CNC Axis a programmable direction of motion. It is like the table on a conventional milling machine only there isn't normally a handle to crank to move it. The CNC Control moves it through a program which is the subject of the next section.

An axis can move along a straight line in which case it’s called a linear axis, or rotate along a circular path in that case called a rotary axis. The more axes, the more complex the machine. 3-Axis machine tools with all linear axes, and 5-Axis machine tools with three linear axes and two rotary axes are common.
The CNC Program:
A CNC Program is a set of instructions that the CNC Control reads then commands the machine to perform a certain task. The program can be written manually but for more complex parts writing programs manually becomes much more difficult. To simplify the programming process, CAD/CAM software can be used with a common pc. The CAD (computer aided design) part of the software is used to draw the part. The CAM (computer aided manufacturing) part of the software is used to create the CNC Program.

Need a job? People make a good wage and develop a rewarding career working with CNC machines. The industry uses people whom design, build, install, maintain, operate, program, and teach CNC.

I can already tell that''s gonna be super hlefpul.
Akanksha 09/09/2012