CNC Machinist Calculator UltraHome › G-codes › Centroid CNC12 Acorn › G90
G90 Absolute positioning / OD and ID turning cycle
Centroid CNC12 Acorn G-code · Mill, Lathe
On mills: Absolute positioning
Positions are measured from the active part zero.
Format
G90
Addresses
| Address | What it does |
|---|---|
none | No words |
How it works
Modal. Default.
Example program
G20 G90 ; INCH, ABSOLUTE
G54 G0 X2. Y3. ; GO TO X2 Y3 FROM PART ZERO
G91 X1. ; MOVE 1 INCH MORE IN X
G90 ; BACK TO ABSOLUTE
G54 G0 X2. Y3. ; GO TO X2 Y3 FROM PART ZERO
G91 X1. ; MOVE 1 INCH MORE IN X
G90 ; BACK TO ABSOLUTE
Example is in inch. Check offsets and clearances first.
Watch out for
- On a Centroid lathe G90 is a turning cycle, not absolute mode. The lathe uses X Z for absolute and U W for incremental.
On lathes: OD and ID turning cycle
One pass box cycle: rapid in, feed along Z, feed out in X, rapid back to the start. R adds a taper. Use X Z or U W.
Format
G90 X or U Z or W [R] [P] [L] F
Addresses
| Address | What it does |
|---|---|
X Z | Cut diameter and end of cut |
R | Taper, X start offset as radius |
P | Length of a feed return move |
L | Dwell before the X move out |
F | Feed |
How it works
Modal while cutting. Cancel with G80 or a motion code.
Example program
G20 G99 G40 G97 ; INCH, FEED PER REV, RPM MODE
T0101 ; TOOL 1 WITH OFFSET 1
G97 S1000 M3
G0 X2.5 Z.1 M8 ; START POINT
…
T0101 ; TOOL 1 WITH OFFSET 1
G97 S1000 M3
G0 X2.5 Z.1 M8 ; START POINT
…
The full 8-line example is in the app. Example is in inch. Check offsets and clearances first.
Watch out for
- On a Centroid lathe G90 is this cycle, not absolute mode. Use U and W for incremental.
- R is not affected by diameter mode. X is.
Related codes
G90 on other controls
The same number can mean something different on another control.
| Control | Meaning |
|---|---|
| Fanuc | Absolute programming |
| Haas NGC | Absolute positioning |
| Mazak (EIA) | Absolute programming |
| Okuma OSP | Absolute programming |
| Mitsubishi M70 M80 | Absolute programming |
| Brother Speedio | Absolute programming |
| Siemens 840D 828D | Absolute dimensions |
| Heidenhain TNC (ISO) | Absolute dimensions |
| Fagor 8055 8065 | Absolute programming |
| LinuxCNC Tormach | Absolute distance mode |
| Mach3 Mach4 | Absolute mode |
| Hurco WinMax (NC) | Absolute mode |
| Fadal | Absolute positioning |
| Swiss (Citizen Star) | OD turning cycle |
Every G-code for Centroid CNC12 Acorn 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 G90 in the app All Centroid CNC12 Acorn G-codes