G-code

What is G-code? And Is it easy to learn?

G-code, short for “geometric code,” is a programming language used to control CNC (Computer Numerical Control) machines. CNC machines are used in various industries, such as manufacturing, woodworking, and metalworking, for tasks like milling, turning, cutting, and engraving. G-code provides a set of instructions that tell the CNC machine how to move, position the tool, and perform specific operations.

G-code commands dictate the machine’s actions, such as linear or circular movements, spindle speed, coolant control, and more. These commands are usually generated by CAM (Computer-Aided Manufacturing) software, which converts a digital design into G-code. However, machinists can also write and edit G-code manually if needed.

Learning G-code can be relatively easy if you have a basic understanding of CNC machining concepts and coordinate systems. The commands are generally simple and straightforward, with each command representing a specific action or movement. To become proficient in G-code, it’s essential to practice and familiarize yourself with the most common commands and their applications.

It’s also important to remember that different CNC machines and controllers might use slightly different G-code commands or variations. As you learn G-code, it’s crucial to consult the documentation for the specific machine and controller you’ll be working with to ensure you’re using the correct commands.

In summary, G-code is a programming language for CNC machines, and while it might take some time and practice, it’s generally considered easy to learn if you’re familiar with the basics of CNC machining.

For more information on how to use Gcode please checkout CNC Cookbook’s Gcode Simulator.

How is G-Code Used?

G-code is a programming language used to control CNC machines, which play a pivotal role in various industries such as manufacturing, metalworking, and woodworking. It provides a set of instructions that dictate the machine’s movements and actions to produce a desired part or workpiece. Typically generated by CAM software, G-code translates a digital design into a language the CNC machine can understand, guiding the tool’s path, feed rates, spindle speeds, and other operations. Although most machinists rely on CAM software, manual G-code writing and editing are still crucial skills, especially for fine-tuning or troubleshooting. By converting intricate designs into a series of precise machine commands, G-code has revolutionized the manufacturing process, enabling unparalleled accuracy, repeatability, and efficiency in creating complex parts.

Is G-Code Easy to Learn?

G-code, as the programming language for CNC machines, is generally considered easy to learn for those with a basic understanding of CNC machining concepts and coordinate systems. The language comprises simple and clear commands, each representing a specific action or movement for the machine. Learning G-code involves familiarizing oneself with the most common commands and their applications. However, it’s important to note that different CNC machines and controllers may use slightly varied G-code commands. As a result, consulting the documentation for the specific machine and controller is essential when learning G-code. While mastering G-code may require practice and time, its straightforward nature and the availability of learning resources make it accessible to anyone dedicated to understanding CNC machining processes.

How to Learn G-Code

To learn G-code, the programming language for CNC machines, start by acquiring a foundational understanding of CNC machining concepts, coordinate systems, and the various operations performed by CNC machines. Numerous online resources, tutorials, and forums are available to help you grasp the basics of G-code and its most common commands. Practicing with simulation software or CNC simulators allows you to write and test G-code programs in a safe, virtual environment before running them on actual machines.

As you progress, consult the documentation for the specific CNC machine and controller you will be working with, since G-code commands may vary slightly between them. Engaging with online communities, seeking advice from experienced machinists, and experimenting with real-world projects will further solidify your understanding of G-code, enabling you to become proficient in using and modifying it for a wide range of CNC machining applications.

Breaking Down Defense Distributeds G-Code for the Ghost Gunner 3

Let’s take the time to go over some of the code in a DD. file. We are going to be taking a look at DD’s AR308 cut codes first, a lot of this code can be reused it’s simply identifying the information. We are going to do the best we can to break it down.

G-code Commands

Gcode Command Library

  • G00: Rapid positioning
  • G01: Linear interpolation
  • G02: Circular interpolation, clockwise
  • G03: Circular interpolation, counter-clockwise
  • G04: Dwell
  • G05: High-speed machining mode
  • G07: Imaginary axis designation
  • G09: Exact stop check
  • G10: Programmable data input
  • G11: Data write cancel
  • G12: Circular pocket milling, clockwise
  • G13: Circular pocket milling, counter-clockwise
  • G17: XY plane selection
  • G18: ZX plane selection
  • G19: YZ plane selection
  • G20: Inch unit selection
  • G21: Metric unit selection
  • G22: Stored stroke check function on
  • G23: Stored stroke check function off
  • G25: Spindle speed fluctuation detection on
  • G26: Spindle speed fluctuation detection off
  • G27: Reference point return check
  • G28: Reference point return
  • G29: Return from reference point
  • G30: Return to secondary reference point
  • G31: Skip function
  • G32: Thread cutting
  • G33: Thread cutting with synchronized spindle
  • G34: Variable lead threading
  • G40: Cutter radius compensation cancel
  • G41: Cutter radius compensation left
  • G42: Cutter radius compensation right
  • G43: Tool length compensation positive
  • G44: Tool length compensation negative
  • G45: Tool offset increase
  • G46: Tool offset decrease
  • G47: Tool offset double increase
  • G48: Tool offset double decrease
  • G49: Tool length compensation cancel
  • G50: Scaling function cancel
  • G51: Scaling function
  • G52: Local coordinate system setting
  • G53: Machine coordinate system setting
  • G54: Work coordinate system 1
  • G55: Work coordinate system 2
  • G56: Work coordinate system 3
  • G57: Work coordinate system 4
  • G58: Work coordinate system 5
  • G59: Work coordinate system 6
  • G61: Exact stop mode
  • G62: Automatic corner override
  • G63: Tapping mode
  • G64: Cutting mode
  • G65: Custom macro simple call
  • G66: Custom macro modal call
  • G67: Custom macro modal call cancel
  • G68: Coordinate system rotation
  • G69: Coordinate system rotation cancel
  • G70: Inch pattern
  • G71: Metric pattern
  • G73: High-speed peck drilling cycle
  • G74: Left-hand tapping cycle
  • G75: OD/ID grooving cycle
  • G76: Fine boring cycle
  • G77: Back boring cycle
  • G78: Tapping cycle
  • G80: Canned cycle cancel
  • G81: Drilling cycle, spot boring
  • G82: Counter boring cycle
  • G83: Deep hole drilling cycle
  • G84: Tapping cycle, right-hand
  • G85: Boring cycle, no dwell, feed out 73

Breaking Down DD’s 02_Trig_Align

Here’s a breakdown of the G-code in the 2nd file;

  1. G21: This command sets the unit of measurement to millimeters. All coordinates and dimensions following this command will be interpreted in millimeters.
  2. G90: This command sets the coordinate system to absolute mode. This means that all coordinates specified in the program will be given with respect to the machine’s origin (0,0,0).
  3. G55: This command selects Work Coordinate System 2. It allows the machinist to define a separate coordinate system for the workpiece, which is useful when working on multiple parts or when there is a need to shift between different origins.
  4. G0 (or G00): Rapid positioning. This command moves the tool quickly to a specified position without engaging the cutting process. It’s used to reduce non-productive time between cutting operations.
  5. G53: This command is used to move the machine’s axes to an absolute position in the machine coordinate system. It temporarily cancels any active work coordinate system offsets (such as G55).
  6. Z-1: This is a coordinate value, instructing the tool to move to a position 1 millimeter below the machine’s Z-axis zero point.
  7. X21.5 and Y-80: These are coordinate values, instructing the tool to move to a position of 21.5 millimeters along the X-axis and -80 millimeters along the Y-axis.
  8. G0 Z-20: This command rapidly moves the tool to a position 20 millimeters below the machine’s Z-axis zero point.
  9. G4: Dwell command. This command pauses the machine for a specified amount of time.
  10. P0: This is a parameter for the dwell command (G4). In this case, it specifies a pause of 0 seconds. Since the dwell time is set to 0, the machine will not pause and continue executing the next command immediately.

The code provided sets the units to millimeters, uses an absolute coordinate system, and selects Work Coordinate System 2 (G21 G90 G55). It then rapidly moves the tool to a position 1 millimeter below the Z-axis zero point in the machine coordinate system (G0 G53 Z-1). Next, it moves the tool to the center of the AR mag well for installation (G0 X21.5 Y-80) and moves it 20 millimeters below the Z-axis zero point (G0 Z-20). Finally, it includes a dwell command with a 0-second pause (G4P0), meaning the machine will not pause and continue executing the next command immediately.

DD’s AR 308 Code Breakdown #02

#01_Home_Tool_Install

#01_Home_Tool_Install Breakdown

Here’s a breakdown of the G-code in the first file;

  1. (AR308 2018.08.20): This is a comment, providing information about the program or version (in this case, AR308 with a date of 2018.08.20).
  2. $X: This command unlocks the machine, allowing it to accept G-code commands and resume operation after an alarm or stop.
  3. G10 L2 Pn X0 Y0 Z0 (n = 1 to 6): These commands set the Work Coordinate System (WCS) offsets for systems P1 to P6 to zero. This effectively zeroes out the offsets for each WCS.
  4. M5: This command stops the spindle motor.
  5. G90 G21: This line combines two commands. G90 sets the coordinate system to absolute mode, and G21 sets the unit of measurement to millimeters.
  6. $H: This command homes the machine, returning all axes to their predefined home positions.
  7. G10 L20 P2 X0 Y0 Z0: This command sets the current position of the machine as the zero point (origin) for Work Coordinate System 2 (WCS2).
  8. G53 G0 X-1 Y-70: This line combines two commands. G53 is used to move the machine’s axes to an absolute position in the machine coordinate system, and G0 is a rapid positioning command. The tool moves quickly to a position of X = -1 and Y = -70 in the machine coordinate system.
  9. G53 G0 Z-60.5: This line also combines two commands, G53 and G0. The tool moves quickly to a position of Z = -60.5 in the machine coordinate system. This move is typically performed to plunge the tool to a specified depth for tool installation or removal.

The provided G-code zeroes out the WCS offsets, stops the spindle motor, sets the coordinate system to absolute mode, and specifies the unit of measurement in millimeters. The machine is then homed, and WCS2 is set to the home position. Finally, the machine moves to the center (X = -1, Y = -70) and plunges to a depth of Z = -60.5 for tool installation.