CNC Machinist Calculator UltraG31 Skip function
Fanuc G-code · Mill, Lathe
On mills: Skip function
Feeds the axes toward the end point and stops as soon as the skip signal comes on, usually from a probe. The position where it tripped is stored in system variables.
Format
Addresses
| Address | What it does |
|---|---|
X Y Z | End point if no signal comes |
F | Feed rate for the probing move |
How it works
One shot, group 00.
Example program
G43 H20 Z-.2 (PROBE DOWN BESIDE PART)
G31 X.1 F10. (PROBE TOWARD PART EDGE)
#100=#5061 (SAVE X SKIP POSITION)
…
The full 5-line example is in the app. Example is in inch. Check offsets and clearances first.
Watch out for
- If the signal never comes the axis goes all the way to the end point. Keep the target just past the expected touch.
- Skip positions are read from system variables, starting at 5061 for the first axis.
- Cancel cutter compensation before G31 or an alarm occurs.
On lathes: Skip function
Feeds the axis toward a point and stops the move the moment a skip signal arrives, such as a probe or tool setter. The stop position is saved in system variables.
Format
Addresses
| Address | What it does |
|---|---|
X Z | Target point, past the expected contact |
U W | Incremental target |
F | Feed rate for the probing move |
How it works
Non-modal.
Example program
G00 X3. Z.2 (APPROACH PROBE)
G31 Z-.2 F5. (PROBE FACE)
G00 Z.5 (BACK OFF)
Example is in inch. Check offsets and clearances first.
Watch out for
- If no signal arrives the axis goes all the way to the target. Keep the target short.
- Turn off tool nose radius compensation first.
- Use a slow feed for repeatable readings.
Related codes
G31 on other controls
The same number can mean something different on another control.
| Control | Meaning |
|---|---|
| Haas NGC | Skip function, probe move |
| Okuma OSP | Skip function |
| Mitsubishi M70 M80 | Skip function |
| Brother Speedio | Skip function |
| Heidenhain TNC (ISO) | Blank form max point |
| Mach3 Mach4 | Probe move |
| Hurco WinMax (NC) | Skip, probing move |
| Fadal | Probe touch function |
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