G17 XY / G18 XZ / G19 YZ plane selection (Group 02)
The face of the workpiece to have a circular milling operation (G02, G03, G12, G13) done to it must have two of the three main axes (X, Y and Z) selected. One of three G codes is used to select the plane, G17 for XY, G18 for XZ, and G19 for YZ. Each is modal and applies to all subsequent circular motions. The default plane selection is G17, which means that a circular motion in the XY plane can be programmed without selecting G17. Plane selection also applies to G12 and G13, circular pocket milling, (always in the XY plane).
If cutter radius compensation is selected (G41 or G42), only use the XY plane (G17) for circular motion.
G17 Defined – Circular motion with the operator looking down on the XY table from above. This defines the motion of the tool relative to the table.
G18 Defined – Circular motion is defined as the motion for the operator looking from the rear of the machine toward the front control panel.
G19 Defined – Circular motion is defined as the motion for the operator looking across the table from the side of the machine where the control panel is mounted.
G17 XY / G18 XZ / G19 YZ plane selection