The Function of G Codes in CNC Cutting
ALL Function of G Codes in CNC Cutting
G code, which is also known as G programming language, is the coding standard of CNC machines. CNC machines are used for cutting various materials such as plastic and metal and as these machines are controlled by a computerized system, they need a code to perform any given task.
If you have a CNC cutting machine like CNC Plasma cutting machine, CNC Laser cutting machine, CNC Milling machine, then with the help of G-codes, you can command the machine to cut something according to your requirements. G-codes let you determine the cutting speed and cutting tool’s axis.
G-codes are called so because the commands of this code used for CNC cutting begins with the letter “G”. Generally, it tells the machine what action it needs to perform. For example:
# Shift the cutting tool to the place where it’s required for cutting something.
# Move in an arc form or straight line.
# Bore a hole, cut any material as per the required measurement or shape the perimeter of a work piece.
# Offset setting.
# Change the coordinate system.
Most Used G-Codes
CNC machines are manufactured by a number of companies and G-codes may not be the same across all the models as the software package used in various models is not identical. A CNC cutting machine features three axis cutting tools and here are some of the codes that can help you in your work:
# G00: Whether the machine features 2 or 3 axis, when you use this code, it rotates all the axis at a maximum speed until its vector is obtained. Remember that the movement of axis does not happen in a straight line. Therefore, you should be very careful to avoid a crash.
# G01: This is one of the most common codes used for CNC cutting. The program gets an idea of the start and end points, and then calculates the path between them to make sure the final cutting is linear.
# G02: This code is used for clockwise circular interpolation. With the help of this code, you can determine the X, Y, Z axis and size of the radius arc to swing the cutting tool. In order to define the radius, you need to write R+ (less than 180 degree) or R- (greater than 180 degree) with the G02 code.
# G03: It does exactly the same thing. However, this time, the circular interpolation is counter clockwise.
# G04: This code is used for setting the dwell time. “P” defines the exact dwell time. The time is generally set in milliseconds. For example, if you need the CNC machine to dwell for 5 milliseconds, then the code should be G04 P5000 (P1000 means 1 millisecond). Don’t forget that in most cases, dwell needs to last for 1-2 full spindle rotation, which takes much less than 1 second. Therefore, while setting the dwell time, you must be very careful because a long dwell time means unnecessary waste of time and money.
# G20: It’s used for programming in inches, mostly in countries like the UK, USA and Canada.
#G21: This code is used for programming in millimeters all over the world. However, if you want to be an expert of CNC cutting, you must know the proper use of both G20 and G21 codes.
# G28: It takes the cutting tool to the “home” position.
#G29: Does exactly the opposite. It commands the machine to go to a particular XYZ position, returning from the “home” position.
I have mentioned only some G-codes in this article and there are a lot more than can’t be included here. These codes are very important and you must know all of them to run your CNC Cutting machine properly. G-codes help you determine the cutting line, depth and much more. Therefore, before you buy a CNC cutter, memorize (or print and paste) the most important functions so that after installation of the CNC cutting machine, you and your other workers can do their job effortlessly.