Why Is the Z-Probe Not Working on My Genmitsu 3018-PROVer V2?
Exact model: Genmitsu 3018-PROVer V2
Choose the situation that matches what your machine actually does. Follow that repair route and check its result before trying another.
Safety: Remove cutting tools and disconnect both 24 V and USB before moving connectors or servicing axes.
The probe input never changes or starts already triggered
When this applies: Before commanding any Z movement, test the contact input with the plate separate from the clip.
What this suggests: OPEN/untriggered must change to TRIGGERED only on contact. Always triggered may produce ALARM:4; never triggered suggests an open lead or contact problem.
What to check
- Power down USB and 24 V before inspecting connections. The V2 probe lead must plug into the board port labeled Probe, not Z-LIM.
- Clip onto exposed conductive tool metal, not paint or an insulated coating. With the spindle stopped, manually touch the probe plate to the clip/contact and inspect the GRBL probe input state.
- Only use a continuity meter on an isolated, unpowered lead.
How to correct it
- Repair the broken clip or lead, or replace the confirmed defective compatible probe assembly.
- If a verified-good lead still reports the wrong state, back up GRBL $$ settings and compare the actual V2 probe-invert ($6) configuration with the matching machine baseline; do not blindly enter $6=1.
Check the result: Repeat the stationary touch test until both states are reliable before permitting automated probing.
Input changes correctly, but automated probing fails
When this applies: A static touch test succeeds but the Z probe still throws ALARM:4/5, fails to contact, or establishes the wrong Z zero.
What this suggests: ALARM:4 means the probe is unexpectedly triggered at the start; ALARM:5 means contact was not achieved within the travel. The two GRBL alarm codes require different corrections.
What to check
- Measure the actual thickness of YOUR touch plate with calipers; do not assume a sample value such as 14.09 mm or the differing example values in V2 documents.
- Confirm the probe macro/Candle tool-offset value matches that measured plate and that the programmed downward probe travel stays within the available safe Z travel.
- Before running G38.2, place the tool ABOVE the plate with the spindle off and verify the clip contact is secure.
How to correct it
- For ALARM:4, separate unintentionally touching contacts and repeat the static state test.
- For ALARM:5, correct plate placement, start height and safe probing travel; do not increase travel past a mechanical limit.
- For a wrong work zero, correct the measured plate thickness/offset rather than replacing a working probe.
Check the result: On safe contact Z must stop immediately. Jog upward, then confirm work zero against scrap with a small controlled move before running a cutting job.
Confirm the repair
The input changes correctly, Z approaches and stops on contact, and the resulting work-zero passes a scrap-material check without digging into the bed.