CNC Machining is a process used in the manufacturing sector that involves the use of computers to control machine tools. Tools that can be controlled in this manner include lathes, mills, routers and grinders. The CNC in CNC Machining stands for Computer Numerical Control.
History of CNC
Computer Numerical Control ( CNC ) is an automation system of electronics utilizing computer processors to control special motors ( servos ) mounted on traditional machine tools such as mills, lathes, drills, grinders, routers, electrical discharge machines ( EDM ), and many other variations of equipment. It first appeared sometime in the early 1970s with several companies and individuals claiming to have first developed the principle. The idea is for an operator to provide a series of programmed moves that will result in the movement of the machine tool cutter or shaper through a part to be machined.
In the past, these movements were provided by manually operated levers or handles. Some automatic operation was achieved using adjustable cams. Eventually at some point in the 1940s there was an innovative idea of attaching special motors called servos to the machine tools. These motors worked with a concept called closed loop feedback to allow very precise positioning of the shaft. By use of an electronic position measuring device ( encoder or resolver ) it was possible to send a very specific position request to the motor and ultimately the machine tool. These positions were called coordinates and were taken from the Cartesian coordinate system. Initially, the entry of the coordinates into the machine NC control was done using punch tapes but this eventually was superseded with the advent of the modern computer. The new form of NC utilizing the power of a computer processor was called CNC. Today the technology has advanced to the point where a designer can create an imagined part in a CAD ( computer aided design ) computer program. The virtual part can then be processed by another piece of software called a CAM ( computer aided manufacturing ) program. This CAM software converts the virtual part into a series of computer program commands that the machine tool CNC control can ‘understand’.
CNC affects us in many ways since it has been so successfully integrated in just about all forms of manufacturing. If you have handled anything made of plastic or metal there is a very good chance that CNC played a significant role in it’s creation.
