Programming Computer Numerical Controlled Machines With G-codes

Ever since the industrial revolution started, the demand to create precise instruments and products is an important factor in large scale manufacturing. Belts, screws, Drills and all movable parts needed to create other products in the assembly line must all be exact and compatible, thus extra care must be taken in order to ensure that all moving parts match perfectly. Computer Numerical Controlled programming has become an extremely important part of this process.

Computer Numerical Controlled Machines are useless without any programming. CNC ’s rely on pure hard codes in order to execute commands that the Machine Operator wants to do, therefore not only is it needed to learn the mechanics of the whole Computer Numerical Controlled Machine but it is also at the utmost importance that the Machine operator knows how to communicate with the machine, and that is by using G-codes.

Preparatory code/ functions or much commonly called as G-codes are functions in the Computer Numerical Control programming language. The G-codes job is to manage the position of the tool as well as control the step by step commands during the actual work. Basically the G-codes are the most important part of the Computer Numerical Control Programming algorithm.

There are other codes involved in the programming of CNC ’s such as M-codes that manages the machine, T-codes for managing the tools, and F-codes for the tool feed and tool speed controls. All of these codes are created in a Computer Aided Manufacturing (CAM) software.

G codes as well as the others use the RS-274D as the recommended standard for the Computer Numerical Controlled Machines. This standard was developed by the Electronic Industry association during the 1960’s. These standards provide a basis for the creation of Computer Numerical Controlled Programs.

First designs of these standards came from punched paper tapes as the medium standard for data interchange, but now ASCII character bit patterns are the standard for the representation.

G-Codes

Lets discuss the g-codes further, as what I have said earlier G- codes constitute only a part of the Computer Numerical Control Program, in the whole programming algorithm, they are denoted by the letter G, Basically it is a code telling the machine what kinds of actions to perform in a step by step basis, examples of these actions would be rapid move, controlled feed moves that would bore holes, a work piece cut routed to a specific dimension, change a pallet, and set a tool information such as offset.

After creating each part of the codes, the algorithm is compiled in the Computer Aided Manufacturing (CAM) software. The CAM software basically use translators called post processors to output the code optimized for a certain machine type. Often times, post-processors are often used to allow users to enable further customization.

G-codes can also be used to create outputs for Computer Aided Design systems used to design printed circuit boards (PCB). Any software must be customized for each type of machine tool that it will be used to program. Some G-codes are written by hand for volume production jobs.

Some Computer Numerical Controlled machines use conversational programming. Conversational programming is an easier way to program CNC machines because it is more “user friendly” because it uses a wizard like program that hides the G-codes into plain view. Some Popular examples of this kind of CNC machines are the Southwestern Industries’ Proto TRAK, Mazak’s Mazatrol, and Mori Seiki’s CAPS conversational software.

Conclusion

With these kinds of further sophistication in programming Computer Numerical Controlled Machines, it is expected in the future that programming would be much easier for its machine operators.


Gargi Nath

I am Gargi Nath from Kolkata,India.Please visit my site at http://CNC -applications.blogspot.com for an insight into CNC Machines & its programming.