CNC Machinist Calculator UltraG90 Absolute programming / Outer and inner diameter turning cycle
Fanuc G-code · Mill, Lathe
On mills: Absolute programming
Axis values are positions measured from the active work zero. The normal mode for most programs.
Format
G90
How it works
Modal, group 03.
Example program
G17 G20 G40 G49 G80 G90 (SAFE START, ABSOLUTE)
G54 G00 X1. Y1. (POSITION FROM PART ZERO)
X2. (NOW AT X2. FROM ZERO, NOT 2 MORE)
G54 G00 X1. Y1. (POSITION FROM PART ZERO)
X2. (NOW AT X2. FROM ZERO, NOT 2 MORE)
Example is in inch. Check offsets and clearances first.
Watch out for
- On a Fanuc lathe with the standard G code system, G90 is a turning cycle, not absolute mode. This entry is for mills only.
- Return to G90 right after any G91 G28 line.
On lathes: Outer and inner diameter turning cycle
In G code system A, G90 is a single pass turning cycle, not absolute mode. Each line rapids in, turns along Z, feeds out and rapids back. Add R for a taper.
Format
G90 X(U) Z(W) [R] F
Addresses
| Address | What it does |
|---|---|
X Z | End point of the cut, X as a diameter |
U W | Incremental end point |
R | Taper, radius difference from start to end of the cut. Minus when the diameter grows toward the chuck |
F | Feed |
How it works
Modal, group 01. Each new X line runs another pass.
Example program
T0101 (OD ROUGH TOOL)
G97 S1200 M03 (CONSTANT RPM)
G00 X2.1 Z.1 M08 (CYCLE START POINT)
G90 X1.9 Z-1.5 F.01 (PASS 1)
…
G97 S1200 M03 (CONSTANT RPM)
G00 X2.1 Z.1 M08 (CYCLE START POINT)
G90 X1.9 Z-1.5 F.01 (PASS 1)
…
The full 7-line example is in the app. Example is in inch. Check offsets and clearances first.
Watch out for
- System A has no G90 absolute and G91 incremental. Use X and Z for absolute and U and W for incremental.
- Cancel it with G00 or G01 before the next move, or the next line runs another pass.
Related codes
G90 on other controls
The same number can mean something different on another control.
| Control | Meaning |
|---|---|
| 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 |
| Centroid CNC12 Acorn | Absolute positioning |
| Hurco WinMax (NC) | Absolute mode |
| Fadal | Absolute positioning |
| Swiss (Citizen Star) | OD turning cycle |
Every G-code for Fanuc 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 Fanuc G-codes