Understanding CNC - Computer Numerical Control

Have you ever asked yourself how machines in a factory know exactly when to stop making the parts theyre supposed to make? Well, this is all because of Computer Numerical Control (CNC). But to understand CNC, you have to know what Numerical Control (NC) is.
HISTORY
NC machines were first introduced after the 2nd world war as mass production became the trend. These machines were given a set of instructions in punched cards. However, these machines were hard-wired and their parameters were difficult to change.
These NC machines still required a great deal of human intervention. To illustrate this point, try to take a look at a drill press. A lot of actions have to be taken in order to manufacture a product. The process is actually so complicated that a person has to do something almost every step of the production process. This created an avenue for errors to take place as the likelihood of fatigue increased with the quantity growth.
CNC then came into the picture when computers were introduced. Punched cards were replaced by floppy disks, cables, and other software transfer media. This made it easier to manage and edit data.
Production and manufacturing were revolutionized by the increased automation of CNC machines. These machines allowed a degree of added control over the quality and consistency of the components that were manufactured without any additional strain on the operators. This reduced the frequency of errors and allowed the operators time to perform additional tasks. Furthermore, this automation allowed a greater degree of flexibility in the way components are held in the manufacturing process.
With the advent of Computer Aided Manufacturing (CAM), even programming CNC machines is a snap. These programs actually take the bulk of the programming process to make the operation less tedious. However, to be an effective programmer of CNC machines, you have to know what the machine youre working on will be doing. That is why machinists are often the best people for the job.
The ease that the machines provide is hinged heavily on the quality of the machine. Low-cost CNC machines oftentimes have many functions that have to be manually activated. High-cost machines, however, are almost fully automated. The operator only has to load or unload workpieces. Once the cycle has been initiated, the operator just has to sit back and watch for any malfunctions. The stress on the operator is so low that some even complain of boredom in the middle of a cycle.
CODING
The programming language that CNC uses is called a G-Code. These codes actually position the parts and do the work. To be able to have a machine work properly, you have to input the correct variables such as axes, reference points, the machine accessories, and whatnot. Every machine has a different set of variables so you have to be careful to take note of the differences.
Aside from the G-Code, logical commands or parametric programming can be used to make the process more time-efficient. This type of programming language shortens lengthy programs with incremental passes. A loop can also be programmed thereby removing the need for coding repetitions.
Because of these features, parametric programming is more efficient than CAM. It allows users to directly and efficiently make performance adjustments. It also allows extensions to the functionality of the machine it is running on.
And that makes CNC.