How to Mill a 360-Degree Circle With G-Codes
- 1). Add "G1 X- Y-" to your G-code program to position the tool at the coordinate where you will begin your circle. The dashes represent the X and Y coordinates that you will specify for the starting point of your circle. The G1 command goes straight to the specified location, which in this case lies in the XY plane.
- 2). Subtract the distance in the X dimension between your starting point and the center of your circle to determine your I offset. Subtract the distance in the Y dimension between your starting point and the center of your circle to determine your J offset. Together, these relative offsets tell your controller how to shape the circle.
- 3). Add "G2 X- Y- I- J-" to your program to move the tool in an arc. The arc ends at the point specified by the X and Y parameters, and it curves around the center specified by the relative offsets I and J, which run along the X and Y axes, respectively. For counterclockwise arcs, use G3 instead of G2.
- 4). Repeat the steps to create arcs which extend to each quadrant of your circle. The quadrant boundaries where your circle has a horizontal or vertical tangent mark four points where the machine has to change directions. Some controllers can handle complete circles automatically.
- 5). Simulate your G-code to verify that the program creates your desired circle. You can now mill a 360-degree circle with G-code.
