G43.4

Format and notes

G43.4 H_ (ON) … G49 (cancel)
G43.5 H_ is the form that writes the tool orientation as a vector (I, J, K)

• Even when the rotary axes move in 5-axis machining, the NC automatically corrects the linear axes so that the tool tip follows the programmed path. It extends the idea of G43 (tool length compensation) to tool orientation and rotary axes
• Because the NC handles the conversion between the tool length and the positional relationship of the machine's rotary axes (kinematics), CAM can output the tool tip path without worrying about the machine configuration. You don't need to regenerate the program when the tool length changes (FANUC development report)
• G43.4 writes the tool orientation as rotary axis angles, and G43.5 writes it as a vector (I, J, K) (Mitsubishi Electric selection guide, assignment in Autodesk's FANUC post-processor)
• Use tool center point control for simultaneous 5-axis machining (the tool orientation changes continuously) and the tilted working plane command (G68.2) for 3+2 machining (set the orientation, then cut with 3 axes)
• If the registered tool length differs from the actual one, the tip error rotates together with the tool. Re-measuring the tool length and calibrating the center of rotation determine the accuracy
• The numbers differ by NC, and it is often an optional function. The number could not be confirmed in FANUC's own public documents (based on a measuring instrument maker's comparison table, Mitsubishi Electric's catalog and CAM post-processor output). Always check the operator's manual

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.