G68.2

Format and notes

G68.2 X_ Y_ Z_ I_ J_ K_ (origin of the tilted plane and three rotation angles)
G53.1 (index the tool perpendicular to the tilted plane)
… 3-axis program, canned cycles …
G69 (cancel)

• Creates a coordinate system (tilted coordinate system) on a tilted plane in space, so you can use ordinary 3-axis programs and canned cycles inside it. Most often used for 3+2 machining (set the orientation with the rotary axes, then cut with the linear axes only)
• G53.1 indexes the rotary axes so the tool is perpendicular to the defined plane. The tilted coordinate system stays linked to the rotary axes after indexing, so you don't need to set the coordinate system again
• The order and meaning of the I, J, K rotations and how the plane is defined differ by model and setting. Mitsubishi Electric's tilted working plane command can define a plane in six ways: Euler angles, roll/pitch/yaw angles, 3 points on a plane, 2 vectors, projection angles, and tool axis direction
• A different function from G68 (2D coordinate rotation within the machining plane). The numbers are similar, so don't confuse them
• The most dangerous case is not noticing a wrong definition until the machine moves. Mitsubishi Electric reports that its function for defining the tilted coordinate system on the screen and checking it in 3D cut the time for defining and checking by 50–60% compared with writing it in the program. Even when writing it in the program, check the orientation with a dry run or simulation before cutting
• The numbers G68.2 and G53.1 were confirmed from the output of a CAM maker's generic FANUC post-processor. FANUC's own public document (a function introduction page) gives only the function name, not the numbers. Mitsubishi Electric's numbers could not be confirmed in public documents either. Always check the operator's manual
• Use G43.4 (tool center point control) for simultaneous 5-axis machining (the tool orientation changes continuously)

Differences between controls and machines

The same code can be written or assigned differently depending on the CNC control and the machine builder. Always check your machine’s manual.

“One source / reference” rows were confirmed in only one source. “CAM post output / reference” rows show what a CAM post processor outputs and could not be confirmed in the control maker’s own public documents.