Computerized Numerical Control / CNC – Smart Factory Glossary

Computerized Numerical Control, or CNC for short, is an automated electronic control system directing the movements of machines and tools. The control system can integrate up to 30 axes thereby allowing workpieces of almost any shape to be manufactured perfectly. Simply put, a computer program controls the motion of mechanical tools. The CNC technology has its roots in numerical control systems reading information for the machine control from punched tapes. The first CNC machine control was launched as early as the 1960s.

 

How a CNC machine works

The machine is controlled by a software program written in a specific programming language. The software program uses interpolation for precise axis motion commands ensuring correct speed and correct position on the machine. A milling machine or laser can then precisely shape the workpiece. The software calculates each position between starting point and endpoint of the tool.

The three basic CNC motion types:

• Point-to-point machining or rapid motion: Only the endpoint of the axis motion is specified and the tool is positioned as quickly as possible to perform a simple processing step such as drill a hole, punch a shape, or spot-weld two sheets of metal.
• Linear machining or straight-line motion is similar to the point-to-point motion, but the speed of the axis motion is exactly controlled to mill a straight groove, for example.

• Contour machining or circular motion has at least two axes enabling any kind of motion. Interpolation is used to calculate axis motion and the commands are synchronized to precisely direct the tool on the calculated path. Additional axes in modern machines even allow rotations of the workpiece during processing. 

   

Benefits of CNC control

Computerized Numerical Control helps implement digital models as physical objects. Even if the manufactured parts are very complex, they are produced with highest precision. As the machine movements are particularly accurate and at the same time very fast, CNC machines increase efficiency in the production of individual parts and series production.

 

What does CNC have to do with MES?

A Manufacturing Execution System (MES) like HYDRA X of MPDV can centrally manage NC programs and setting data and easily send them to the machine. The mApp DNC & Setting Data is an example of such a solution. The operator only needs to select the program from the database and feed the CNC machine via network connection. This reduces setup times and avoids errors because the MES automatically checks during transfer if the selected setting data matches the machine, tool, and produced article.

Source

• Numerical Control: Wikipedia, 18.03.2024 [online] https://en.wikipedia.org/wiki/Numerical_control (requested on 18.03.2024).

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