I believe that if you are engaged in the CNC industry, you must know the G code. After all, only through it can you control the machine tool for processing. But do you want to know more about G-code? Do you really want to improve your abilities through learning? Then don’t miss this article full of useful information. I believe you will gain something after reading it.
What Is G-Code ?
code is the language most commonly used to program CNC machines. It controls the machine tool movement and machining through the machining process, such as positioning, cutting, drilling, tool change, etc., in the form of a instruction code sequence. Now it is also widely used in CNC milling machine, CNC lathe, 3D printer and other automatic production equipments.
It can be said, G code is a the significant basis for modern manufacturing automation and essential means to realize high precision machining.
Types of G-Codes
There are many types of G codes, and I will introduce you to the most common types of G codes below.
1. Motion G Codes
This type of G code controls how and where the machine tool moves.
- G00: Quick positioning. Let the tool move to the specified position at the fastest speed without processing.
- G01: Linear interpolation. The tool moves along a straight line at a specified speed and is often used in cutting operations.
- G02: Clockwise arc interpolation. The tool moves clockwise along an arc path.
- G03: Counterclockwise arc interpolation. The tool moves counterclockwise along an arc path.
2. Coordinate System G Codes
This type of G code sets up and selects the coordinate system for machining.
- G54~G59: Select different workpiece coordinate systems. It is convenient to process different workpieces or positions.
- G92: Set the current coordinate value. Used to temporarily set the coordinates of the machine tool.
3. Programming Mode G Codes
This type of G code sets the programming style and units.
- G20: Programming in inches
- G21: Millimeter unit programming
- G90: Absolute coordinate programming
- G91: Incremental coordinate programming
4. Machining Preparation G Codes
This type of G code is used to set the preparation state before machining.
- G17/G18/G19: used to select the processing plane. G17 is the XY plane, G18 is the ZX plane, and G19 is the YZ plane.
- G40: Cancel tool radius compensation
- G41/G42: Enable tool radius compensation (left/right)
5. Other Function G Codes
These G codes include operations such as pausing and returning to the reference point.
- G28: Return to machine tool reference point
- G04: Pause (delay)
How Does A G-Code Work?
Well, after talking about the types of G codes, let’s talk about how G codes work. Presumably this is what you are more concerned about.
1. Writing Programs
First, the operator or engineer will use G code to write the machining program according to the processing requirements of the part. Each line of code represents a specific action or setting, such as moving, cutting, tool changing, etc.
2. Inputting Programs Into Machine Tools
Next, the written G-code program is input into the control system of the CNC machine (usually through a USB flash drive, network or written directly).
3. Parsing Instructions
When machining begins, the CNC system will read and analyze each G code instruction and translate it into action instructions that the machine tool can understand.
4. Executing Actions
During processing, the machine tool automatically completes the machining process such as positioning, cutting, drilling, and tool change according to the requirements of the G code.
5. Feedback And Monitoring
Of course, monitoring the execution process of G code is essential. The machine tool will provide real-time status feedback during execution, allowing the operator to monitor the progress of the machining process. If necessary, the operator is able to pause, adjust or terminate the program.
How To Read G-Code?
So, since G code is so critical, how to read it? This must be the question in your mind at this moment. Don’t worry, I will tell you how to do it next.
In fact, although the G code looks like a combination of “letters + numbers”, you can understand its meaning as long as you master the basic rules.
First, you need to understand the structure of G code. Each letter represents a different meaning:
- G: Motion or function command
- M: Machine tool auxiliary command
- X/Y/Z: Space coordinates
- F: Feed speed
- S: Spindle speed
- I/J/K: Arc interpolation parameters, defining the distance between the center of the circle and the starting point
Three Examples:
(1) Quick Positioning:
G00 X100 Y50 Z0
- G00: Rapid movement (non-cutting movement)
- X100 Y50 Z0: Move to coordinates (100, 50, 0)
This means that the tool should move to the specified position (100, 50, 0) at the fastest speed without cutting.
(2) Spindle Starts And Cuts:
M03 S1200
G01 X60 Y60 F200
- M03: Spindle starts clockwise
- S1200: Spindle speed 1200 rpm
- G01: Straight line cutting
- X60 Y60: Move to (60, 60)
- F200: Feed speed 200mm/min
The meaning of this g code is to first start the spindle and set the speed, and then cut along a straight line to (60, 60) at a speed of 200mm/min.
(3)Drilling Operations:
G81 X30 Y30 Z-10 R2 F100
- G81: Drilling cycle command
- X30 Y30: Drilling position (30, 30)
- Z-10: drilling depth-10
- R2: Retract height 2
- F100: Feed speed 100mm/min
The meaning of the G code is that the drill bit drills at the (30, 30) position, with a depth of -10, and returns to height 2 after drilling, with a feed speed of 100mm/min.
What Machines Use G-Code?
You have to know that G code is now widely used in various CNC automation equipment. The main ones are as follows:
1. CNC Milling Machine
The most common G-code application equipment, this machine tool is mainly used for milling processing of metal, plastic and other materials.
2. CNC Lathe
This machine tool is used for turning workpieces, such as the outer circle and inner hole of shaft parts.
3. CNC Machining Center
A comprehensive processing equipment that integrates various functions such as milling and drilling. This machine tool is often used for multi-process machining of complex parts.
4. CNC Laser Cutting Machine
This machine tool uses laser beam to cut metal and non-metallic plates, and controls the cutting path through G code.
5. CNC Plasma Cutting Machine
This machine tool uses high-temperature plasma to cut metal sheets, and also controls the motion trajectory through G code.
6. CNC Engraving Machine
This type of machine tool is used for fine engraving and cutting of wood, plastic, acrylic and other materials
7. 3D Printer
Yes, 3D printer also uses g-code. I will explain it to you in detail below. The 3D printer controls the nozzle movement, heating, and extrusion of materials through G codes to achieve layer-by-layer printing.
8. EDM
EDM can precisely process high-hardness metals. It precisely controls the electrode movement through G code.
What Is The G-Code In 3D printing?
As I said above, 3D printing also uses G-code. Essentially, it is a series of instructions that guide the printer on how to operate, thereby transforming the digital model into a physical object.
- Control the print head movement: G code specifies the precise movement of the print head in the X, Y, and Z directions.
- Control the extruder: G code controls the extrusion volume and speed of plastic filament.
- Set Temperature: Used to control the temperature of the nozzle and heating bed.
- Other commands: Such as pause, resume printing, fan switch, etc.
Summary
Okay, so far I have introduced all the content of G code. I believe you will gain a lot after reading the entire article. Nowadays, G code is widely used in the machining industry. If you are a practitioner in this industry, you cannot ignore its importance. In addition, our DSR company is an industry-experienced machining company with a professional team of engineers who can provide you with the best service. If you have any needs, please contact us immediately!
FAQ
Q1: Is G-code programming?
A : I don’t need to say more about this question. Yes, G-code is a programming language. You can use it to edit instructions and let the machine automatically complete various actions according to your requirements.
Q2: Is the G-code standardized?
A: G-code is a standardized CNC programming language. The core syntax and basic instructions are specified by international standards (ISO 6983). This language is widely used in CNC machine tools and 3D printers.
Q3: What are the three basic G-Codes?
A: The three most basic G-code instructions are:
- G0 (quick positioning): This G-code is used to move the equipment to the specified position at the fastest speed without processing, just positioning.
- G1 (linear interpolation): This G code controls the device to move along a straight line at a specified speed.
- G28 (reference point return/origin return): Instructs the device to automatically return to the preset reference point or origin, often used to initialize or reset the device position.
Q4: Are G-Codes universal?
A: Generally speaking, G-codes are universal for most devices. However, due to customization and expansion by different manufacturers and device types, some instructions and parameters may be different.
Q5: How are G Codes different from M codes?
A: The biggest difference between the two is that they control different objects. G-code controls the movement trajectory of the device, such as positioning, interpolation, etc.; The M code controls the auxiliary functions of the equipment, such as starting the spindle, switching coolant, heating, etc.
