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G90.1 Absolute arc centers
Mach3 Mach4 G-code · Mill
I J K in arcs are the absolute position of the arc center in work coordinates. Separate from G90 and G91.
Format
G90.1
Addresses
| Address | What it does |
|---|---|
G90.1 | No address words |
How it works
Modal, arc center group.
Example program
G0 G20 G90 G54 G17 G40 G49 G80 (SAFE START, INCH)
G90.1 (ABSOLUTE IJ)
T1 M6 (TOOL CHANGE)
G0 X3.0 Y0 (START)
…
G90.1 (ABSOLUTE IJ)
T1 M6 (TOOL CHANGE)
G0 X3.0 Y0 (START)
…
The full 7-line example is in the app. Example is in inch. Check offsets and clearances first.
Watch out for
- Most Fanuc style posts output incremental I J. Running them in G90.1 draws huge wrong arcs.
- This overrides the IJ mode in the configuration.
Related codes
G90.1 on other controls
The same number can mean something different on another control.
| Control | Meaning |
|---|---|
| LinuxCNC Tormach | Absolute arc center mode |
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