G68 is a G-code command used in Computer Numerical Control (CNC) machining. It is a preparatory command that defines a cutter compensation mode, allowing the machine to automatically adjust the toolpath to account for the tool's diameter.
How G68 Works:
- Tool Diameter Compensation: G68 instructs the CNC machine to compensate for the tool's radius when cutting. This means the machine will move the tool along a path that is offset from the programmed path by the tool's radius.
- Types of Compensation: G68 can be used for both left and right tool diameter compensation.
- Tool Path Adjustment: The machine automatically adjusts the toolpath based on the specified compensation mode.
Advantages of G68:
- Improved Accuracy: G68 helps to achieve more accurate machining by compensating for the tool's size.
- Simplified Programming: It simplifies programming by eliminating the need to manually offset toolpaths for each tool diameter.
- Increased Efficiency: G68 saves time and effort by automating the tool compensation process.
Examples:
- G68 X0 Y0 R0.5: This command sets the tool diameter compensation to the right, with a radius of 0.5 units.
- G68 X0 Y0 R-0.5: This command sets the tool diameter compensation to the left, with a radius of 0.5 units.
Practical Insights:
- G68 is commonly used in CNC milling operations, particularly for contouring and pocketing.
- It is essential to select the correct compensation mode (left or right) based on the tool's position relative to the programmed path.
- Using G68 can significantly improve the quality and efficiency of CNC machining operations.
