I cut most of a cabinet yesterday on my machine (woohoo!) but today when I went to cut the back I started having trouble probing.
When I start a job, it has me attach the probe (all good) and then the bit slowly starts moving downwards. After 5-10mm of downward travel, I get the following error message in my FluidNC terminal:
[MSG:INFO: ALARM: Probe Fail Contact]
ALARM:5
Probe fail. Probe did not contact the workpiece within the programmed travel for G38.2 and G38.4.
and the Z-axis crashes down to the work top. The really weird part is that if I retry (re-home Z, and move even closer to the tabletop) it claims it’s starting to probe, but actually moves upwards and will even move up so high that the z-limit stubs are pushed slightly upwards (if I let it, I only did that once.)
So the bad initial probe breaks something in the machine that stays broken until I reboot FluidNC. I was cutting just fine (including probing) on this machine less than 12 hours ago, so I have no idea what could be happening here. Any tips?
I am using the same prelude from EstlCAM as worked fine last night: G38.2 Z-80 F200 P0.5.
The initial probe failures I could chalk up to some loose wiring (maybe something happened overnight) but the reversed second probe seems really bizarre.
If this is on an LR4, that Z-80 should be Z-110. The Z-80 was for the LR3 but the LR4 has more Z travel. So, depending on Z position before you start probing, that could fail on a LR4.
Reversing the direction is still weird and wouldn’t expect that on v3.9.1.
I am using the tiny touch place from the V1E store and a 1/8” single flute upcut bit. The probe has its clamp on the bit and the touch plate against the top of the material.
I’ve confirmed by tapping the plate on the bit and seeing the light on the Jackpot illuminate that it can actually detect the bit.
This reproduces 100% of the time with this file. I’ll try a different file and see if it’s 100% overall, as well as just a plain probe from the UI.
It feels like somehow one of the electrical components is malfunctioning here but I don’t know how to check them.
All right, I came home, ran a standalone probe on the machine (worked) and then tried to cut the same file again and it ran just fine. No idea what happened, the bad behavior before lasted through 4 restarts/attempts to cut this file.
simillar problem. Probe fail. Probe did not contact the workpiece. Does anybody else solved this probe issues? Lowrider v4 FluidNC v3.9.6 (wifi). Probe G38.2
Oh, I did figure out what was happening here. The default probe start instructions contain a limit (Z-80) and if your positioning is wonky – like, you set home to 0 and then probe down more than 80mm – then it will fail in the way I described above.
@Tomas_M , try manually moving your machine to 10-15mm above the workpiece, zeroing all dimensions in FluidNC, and starting again.
@Tomas_M , the other thing to check is that your probe is actually connected. Does the little light blink on the Jackpot board if you touch the probe to the little clampy thing (assuming you are using the V1e touch plate)
Thank you for response, i have tried it now. still not working. Yes, i see green indication light blink on while i keep probe shorted. i guess it is allright.
I bought jackpot and esp32 from elecrow. it was without fluidNC installed. there is no jackpot-fluidNC.bin file in the internet anymore. i installed it stock from official fluidNC page. everything works fine, excluding probe. could it be couse of the problem?
It may be wise to share the exact steps you’ve taken to flash your ESP and the config file you’re using.
Personally, I would not trust an LLM to advise me on setting up the CNC machine. They still often struggle with complex reasoning without a feedback loop. And the consequence for a misconfigured or misconstructed machine could be quite serious.
Regarding your probe issue, could you describe exactly what is the behavior you are seeing and how/when it is triggered?
I followed the guide here: Setting up FluidNC to flash FluidNC onto an ESP32 for my LowRider CNC. The flashing process worked without any issues.
I then uploaded the default config.yaml from the V1 Engineering GitHub repository:
Initially, there were no WiFi settings included, so I manually added them to the config.yaml, saved the file, and re-uploaded. That worked fine — the board connected to WiFi.
I also noticed two motors were spinning in the wrong direction. I corrected this by flipping the motor connectors directly at the TMC2209 drivers, and now all axes move correctly.
Then I began testing the probe using G38.2. I connected the probe to GPIO36 and tried triggering it by manually shorting the signal wire to GND. The Z axis moved down but did not detect the probe contact. It continued until reaching the full probing depth and then returned:
makefile
ALARM:5 – Probe fail. Probe did not contact the workpiece.
I repeated the test many times. I also tried switching the probe to GPIO39 and updated the config.yaml accordingly — same result.
The strange part is: when I short GPIO36 or GPIO39, the green indicator light on the Jackpot board lights up — so I know the pin is receiving a signal.
However, i guess FluidNC fails to detect the probe trigger.