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G91 Incremental dimensions

Heidenhain TNC (ISO) G-code · Mill

Coordinates are distances from the last position. Klartext: an I in front of the axis, for example IX+20.

Format

G91 X Y Z

Addresses

Address	What it does
`X Y Z`	Incremental distances

How it works

Modal. Cancel with G90.

Example program

N130 G98 L1 *
N140 G79 *
N150 G91 X+20 M99 *
N160 Y+20 M99 *
…

The full 6-line example is in the app. Example is in inch. Check offsets and clearances first.

Watch out for

Switch back to G90 after an incremental hole pattern or the next moves will be wrong.

Related codes

G90 · G98

G91 on other controls

The same number can mean something different on another control.

Control	Meaning
Fanuc	Incremental programming
Haas NGC	Incremental positioning
Mazak (EIA)	Incremental programming
Okuma OSP	Incremental programming
Mitsubishi M70 M80	Incremental programming
Brother Speedio	Incremental programming
Siemens 840D 828D	Incremental dimensions
Fagor 8055 8065	Incremental programming
LinuxCNC Tormach	Incremental distance mode
Mach3 Mach4	Incremental mode
Centroid CNC12 Acorn	Incremental positioning
Hurco WinMax (NC)	Incremental mode
Fadal	Incremental positioning

Every G-code for Heidenhain TNC (ISO) in your pocket. The app has the full example programs, search by number or shop word, a line decoder and calculators for tapping, threading and drilling.

Open G91 in the app All Heidenhain TNC G-codes

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