AiVibeCutter Radius Compensation (G41, G42)
Cutter radius compensation makes the CNC offset the tool path by the tool's radius, so the program can follow the part contour. G41 offsets to the left and G42 to the right of the direction of travel, and G40 cancels it.
With cutter radius compensation active, the control calculates a path parallel to the programmed contour, displaced by the radius stored in the tool's offset register. G41 places the tool to the left of the contour when viewed along the direction of travel and G42 places it to the right; G40 cancels compensation. A lead-in move is needed to start compensation and a lead-out move to end it. On lathes, tool nose radius compensation uses the same codes together with the tool tip orientation to correct tapers and arcs cut with a rounded insert.
Compensation lets operators hold contour dimensions by adjusting a radius or wear value instead of editing the program, and lets a reground or different-diameter cutter run the same program. CAM systems can output the centre-line path directly, or a path intended for compensation at the control, often called wear or control compensation.
The control needs look-ahead to handle corners, and an inside corner radius smaller than the tool radius cannot be cut without gouging, which many controls detect and stop. Mixing CAM compensation settings with control compensation incorrectly doubles or omits the offset. New or changed programs using compensation should be checked in simulation before cutting.
Key points
- Offsets the path by the tool radius stored in an offset register
- G41 is left, G42 is right of the direction of travel, G40 cancels
- Lets operators hold sizes by adjusting wear values instead of the program
- Inside corners smaller than the tool radius cannot be cut without gouging
Where AiVibe comes in
AiVibe designs and manufactures the AiAmbA AI Factory: edge devices plus AI agents that let people talk to CNC, PLC and robot controllers in plain language. Agents only propose changes, and a trained operator confirms each one.
Related terms
- Tool Length Offset (G43)CNC & Precision Machining
- G-codeCNC & Precision Machining
- Computer-Aided Manufacturing (CAM)CNC & Precision Machining
- Linear and Circular Interpolation (G01, G02, G03)CNC & Precision Machining
- Tool WearCNC & Precision Machining