The G72.2 is a G-code used in CNC programming to perform a linear copy of a figure along a specified path. This code is particularly useful when you need to duplicate a pattern multiple times on a workpiece without having to write the code for each instance.

Usage Format

The basic format for the G72.2 command is as follows:

G72.2 P.. Q.. (other parameters)

• P: Start of the pattern to be copied.
• Q: End of the pattern to be copied.
• (other parameters): Additional parameters such as the number of copies, spacing, etc.

Explanation

When the G72.2 command is executed, the machine will repeat the operations defined between the P and Q addresses. This allows for efficient and precise duplication of complex patterns. It’s important to note that the P and Q values must match the sequence numbers of the pattern in the program.

Example

Let’s consider a simple example where we want to drill a series of holes in a straight line.

Text Diagram:

| Hole 1 |<--->| Hole 2 |<--->| Hole 3 |

G-code:

N010 G90 G00 X0 Y0
N020 G72.2 P100 Q200 X40.0 Y0 L3
N030 G00 X0 Y0
N040 M30
N100 (Start of Pattern)
N110 G81 X0 Y0 Z-10 R5 F100
N120 M99
N200 (End of Pattern)

In this example:

• N010: Sets the machine to absolute positioning mode and moves the tool to the origin.
• N020: Initiates the G72.2 linear copy command to make 3 copies of the pattern defined from N100 to N200, spaced 40 units apart along the X-axis.
• N030: Returns the tool to the origin after the operation.
• N040: Ends the program.
• N100-N120: Defines the drilling operation to be copied.

This G72.2 example demonstrates how to efficiently create multiple copies of a drilling operation, saving time and reducing the potential for errors in programming.