Learn/GcodePilot/Positioning & offsets
Z Touch-Off Probe
Updated v2.6.0At a glance
- One-click Z touch-off: probe the surface and zero the active WCS Z
- Standalone Touch settings are independent of the fire_torch subroutine
- Optional limit-aware rapid pre-position to lift height before the slow probe
- Ohmic + floating-head probing for plasma; a slagged ohmic auto-falls-back to the floating head with a warning
- Trigger-time input tracking applies the correct ohmic or floating-head takeup and refuses an ambiguous hit
- Lift height, probe feed, and separate takeups are unit-aware and persisted per machine
The Touch button runs a Z touch-off: probe down to the surface and zero the active work offset's Z right there. The caret opens its settings:
- Set Z work — zero Z at the probed surface, or just find the surface without re-zeroing.
- Rapid probe — rapid to lift height above work-Z 0 first, then slow-probe. The rapid is limit-aware: if it would leave the Z travel envelope, it's skipped and the routine probes the whole way down instead.
- Lift height / probe feed — unit-aware inputs that accept expressions, persisted per machine.
- Floating-head / ohmic takeup — separate trigger-to-surface distances for each sensing method.
These are standalone Touch settings. They do not read or rewrite the parameters in your
fire_torch subroutine, so changing a manual touch-off cannot silently change the automatic torch
sequence.
Plasma probing
With a plasma torch, probing watches the floating-head switch and the ohmic ring together and stops on whichever trips first. The controller reports which input was asserted at the instant the probe stopped, and Touch applies that input's takeup. It does not infer the source from a later sample after the Z axis has already decelerated onto the floating head. The retract is measured from the captured trip point before the work offset is set, so normal deceleration cannot shift Z0 below the plate or consume the commanded cut clearance.
Ohmic sensing normally trips first and gives the most direct plate contact; the floating head is the mechanical fallback. A worn torch can slag the ohmic sensor into a stuck-on state — instead of halting, Touch detects it before motion, falls back to floating-head-only sensing, applies the floating-head takeup, zeros at the true surface, and shows a non-blocking warning so you know to service the tip. If both inputs assert together or the source cannot be identified, Touch stops without changing the work offset.
Which inputs are used comes from the roles in the machine's User I/O configuration. A machine with only a floating-head input probes on that input; an ohmic-only machine uses its ohmic input. Missing or conflicting probe configuration fails safely before Z is changed.