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G41 Cutter comp left
Mach3 Mach4 G-code · Mill
Offsets the tool to the left of the path by the tool radius. With climb milling on an outside profile a positive offset makes the part bigger.
Format
G41 [D] [P] X Y
Addresses
| Address | What it does |
|---|---|
D | Tool table number for the diameter |
P | Direct offset value instead of the table |
X Y | Lead in end point |
How it works
Modal, cutter comp group. Cancel with G40.
Example program
G0 G20 G90 G54 G17 G40 G49 G80 (SAFE START, INCH)
T1 M6 (TOOL CHANGE)
S8000 M3 (SPINDLE ON)
G0 X1.5 Y-0.75 (START OFF THE PART)
…
T1 M6 (TOOL CHANGE)
S8000 M3 (SPINDLE ON)
G0 X1.5 Y-0.75 (START OFF THE PART)
…
The full 10-line example is in the app. Example is in inch. Check offsets and clearances first.
Watch out for
- Turn comp on and off on straight moves longer than the radius. Mach4 errors if the comp move is an arc.
- Mach3 D is optional. Without D it uses the tool in the spindle. P gives a direct value. Mach4 P is the actual offset.
- Comp works in G17 only on Mach3. Check the toolpath display for gouges on short moves.
Related codes
G41 on other controls
The same number can mean something different on another control.
| Control | Meaning |
|---|---|
| Fanuc | Cutter compensation left |
| Haas NGC | Cutter compensation left |
| Mazak (EIA) | Cutter radius compensation left |
| Okuma OSP | Cutter radius compensation left |
| Mitsubishi M70 M80 | Cutter radius comp left |
| Brother Speedio | Cutter compensation left |
| Siemens 840D 828D | Tool radius compensation left |
| Heidenhain TNC (ISO) | Radius compensation left |
| Fagor 8055 8065 | Tool radius compensation left |
| LinuxCNC Tormach | Cutter compensation left |
| Centroid CNC12 Acorn | Cutter compensation left |
| Hurco WinMax (NC) | Cutter compensation left |
| Fadal | Cutter radius compensation left, climb |
| Swiss (Citizen Star) | Nose radius compensation left |
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Open G41 in the app All Mach3 Mach4 G-codes