Precision is the hallmark of professional CNC machining. While straight cuts are straightforward, mastering G-Code for precision corner rounding elevates your work from functional to exceptional. In this guide, we will explore how to use circular interpolation to create smooth, accurate radii on your workpieces.
Understanding the Basics: G02 and G03
To round a corner, we move away from linear interpolation (G01) and utilize circular interpolation commands:
- G02: Clockwise circular interpolation.
- G03: Counter-clockwise circular interpolation.
The Mathematical Logic
When rounding a corner, you must account for the Tool Nose Radius. The programmed path follows the center of the tool. To achieve a specific radius (R) on the workpiece, the G-code must reflect the arc's start point, end point, and the radius value.
(Example: Rounding a 10mm Corner)
G01 X40.0 Y50.0 F500 ; Move to start of fillet
G02 X50.0 Y40.0 R10.0 ; Create 10mm radius clockwise
G01 X50.0 Y0.0 ; Continue linear path
Pro-Tips for Perfect Radii
Using the R-command is the simplest method for most modern CNC controllers. However, for full circles or complex arcs, using I, J, and K vectors (incremental distance from start to center) provides higher reliability and prevents geometry errors.
Regularly calibrating your tool offsets and ensuring rigid workholding are essential steps to avoid "chatter" marks during the rounding process, ensuring a mirror-like finish on every corner.
CNC Programming, G-Code, Corner Rounding, Machining Tips, Engineering, CAD/CAM, CNC Tutorial
