Safety first: Use the E-stop, unplug spindle/machine power before touching tools, switches or couplers, and keep hands out of axis travel. Never bypass a hard-limit switch to run a cutting job; do not loosen a powered spindle or jog an axis into its physical end.
Model and version covered
Genmitsu 3018-PROVer V2 with GRBL-compatible controller. Check board marking and firmware before applying GRBL commands; the older 3018-PROVer and V2 Lite do not necessarily have identical connectors.
Version check: Confirm controller, GRBL firmware and actual limit/probe connections before changing parameters or running automated motion.
DIAGNOSE THE CAUSE · APPLY THE FIX · CONFIRM THE RESULT
Find the cause and fix it
Jump to your symptom: 01 · Alarm appears immediately after homing reaches travel stop02 · Homing completes but GRBL enters alarm on subsequent jog03 · Switch or home direction is wrong after board replacement
01
Alarm appears immediately after homing reaches travel stop
HOW TO CHECK & CORRECT THIS CAUSE
- Power off machine motion, check X/Y/Z limit-switch wiring at corresponding labeled controller ports and whether each switch lever is physically reached before the axis hits its hard stop.
- Reposition faulty switch/bracket using V2 installation instructions.
How to tell it is fixed: A supervised homing cycle trips each intended switch without crashing.
02
Homing completes but GRBL enters alarm on subsequent jog
HOW TO CHECK & CORRECT THIS CAUSE
- Confirm homing is complete before issuing jogging commands and that the next move is within configured work envelope.
- Clear alarm with controller's documented unlock/reset only after the mechanical cause is corrected.
How to tell it is fixed: Repeated safe home+jog runs without limit alarm.
03
Switch or home direction is wrong after board replacement
HOW TO CHECK & CORRECT THIS CAUSE
- Restore correct GRBL homing polarity/axis parameters from the *same* V2 firmware profile, not another 3018 GRBL screenshot.
How to tell it is fixed: Each axis moves toward its assigned switch during a short guarded homing test.
Source and model restrictions
Technical baseline: Manufacturer guide or model manual ↗