CNC Machinist Calculator UltraHome › G-codes › LinuxCNC Tormach › G2
G2 Clockwise arc or helix
LinuxCNC Tormach G-code · Mill and lathe
Cuts a clockwise arc in the active plane at feed rate. A move on the third axis turns it into a helix. P sets the number of turns.
Format
G2 X Y [Z] I J [P] F or G2 X Y [Z] R [P] F
Addresses
| Address | What it does |
|---|---|
X Y Z | End point of the arc |
I J K | Center offset from the start point |
R | Arc radius, used instead of I J K |
P | Number of turns, whole number, default 1 |
F | Feed rate |
How it works
Modal, motion group. Stays on until another motion code.
Example program
G20 G17 G40 G49 G54 G80 G90 G94 (INCH, SAFE START)
T3 M6 G43 (.375 THREAD MILL)
S4000 M3
G0 X0.3 Y0 Z0.1 (START AT RADIUS .300)
…
T3 M6 G43 (.375 THREAD MILL)
S4000 M3
G0 X0.3 Y0 Z0.1 (START AT RADIUS .300)
…
The full 7-line example is in the app. Example is in inch. Check offsets and clearances first.
Watch out for
- I J K are incremental from the start point by default (G91.1). G90.1 makes them absolute.
- P adds full turns. P1 is the default. P3 on a full circle gives three full circles, good for helical thread milling.
- R format cannot make a full circle. Use I J K for full circles.
Related codes
G2 on other controls
The same number can mean something different on another control.
| Control | Meaning |
|---|---|
| Fanuc | Circular interpolation clockwise |
| Haas NGC | Circular interpolation clockwise |
| Mazak (EIA) | Circular interpolation, clockwise |
| Okuma OSP | Circular interpolation clockwise |
| Mitsubishi M70 M80 | Circular move clockwise |
| Brother Speedio | Circular interpolation clockwise |
| Siemens 840D 828D | Circular interpolation clockwise |
| Heidenhain TNC (ISO) | Clockwise arc, Cartesian |
| Fagor 8055 8065 | Clockwise circular interpolation |
| Mach3 Mach4 | Clockwise arc |
| Centroid CNC12 Acorn | Clockwise arc or helix |
| Hurco WinMax (NC) | Circular or helical move clockwise |
| Fadal | Circular interpolation clockwise |
| Swiss (Citizen Star) | Circular move clockwise |
Every G-code for LinuxCNC Tormach 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 G2 in the app All LinuxCNC Tormach G-codes