XYZ probe false-positive/wiring issue

I have reached out to Onefinity support regarding a probe issue I am having, and they have sent me here for community help.

Overview: (I am giving these details because I am led to believe this is a power/ground/wiring issue) I am running the Onefinity Woodworker with an 800w 400hz 4pin spindle (GPenny 4 bearing to be exact) and a Huanyang 110v 1.5kw Inverter. I had the spindle cable professionally made with 16/4 double shielded cable. I have verified the spindle cable pin to pigtail wiring and configuration is correct. All Spindle wiring has been double, and triple checked for proper routing. The 110V AC pigtail to the inverter has also been double and triple checked for proper wiring and power (Live=R, Neutral=T, Ground=E.) and the VFD has been configured to run via break-out-box from the controller. The spindle appears to work as it should – except for the probe.

Everything at this point seems wired and working per the manufacturers direction and specifications.

The issue: when connecting the XYZ probe magnet to the spindle armature, the Onefinity controller shows green x,y,z and z indicators – without touching the probe plate to anything. Touching the probe plate to the spindle armature while the magnet is connected makes no change to the probe signal status. Additionally, switching the probe’s I/O from normally-closed to normally-open also results in no change to the signal (I also tried power cycling the controller after changes). Thus, the probe will not work properly as it always gets a false positive when attaching the magnet regardless of the touch plate connectivity.

Things of note: If I hold the magnet end of the probe to the touch plate (with the normal probe plate wire removed) and touch the plate to the spindle armature, the probe works perfectly (other probe wire not connected to anything).

Any help appreciated before I just rewire the probe and have other potential issues.


If you have ground connected from the spindle to the VFD to the controller, then you can probe without attaching the magnet at all. I didn’t see that you tried that - see if just touching the probe to the spindle works without the magnet.

The magnet is “ground”, which is why this works.

If you attach the magnet to the spindle and it “connects” the probe, then the magnet is not ground - flip the wires on the probe.

The probe is a simple circuit that is trying to close - the ground connecting through the VFD to the controller is likely providing you one leg of that circuit that you’re not expecting.

1 Like

Thanks for the reply, Michael.

The only way the probe “works as expected” is by using the magnet end of the probe on the spindle. Using the touch plate wire does not complete the circuit no matter the I/O setting. (Even with the VFD and spindle powered down, if that makes any difference) This leads me to believe that something is wired backwards but I’ve checked everything I can per manufacturer specifications and everything is wired per instruction.

Note: I did have to set the controller to reverse the spindle direction to get the right spin on the spindle, if that offers any insight on the matter.

If you connected a ground wire to spindle body (inside the spindle body) and grounded that to your OF controller, try to disconnect the spindle grounding wire and test the probe functionality.

I have similar issue with my OF touch probe before and now its good after disconnecting my spindle ground. I have yet to ground independently my spindle.

I hope this helps :slight_smile:

You need to get an ohm meter and check continuity to see if you are wired wrong. You also need to check if your spindle body is actually connected to ground most of the Chinese spindles do not connect the ground inside the spindle. It sounds like you probe wires are reversed.

Thanks for the reply, scottjritt

The spindle body is properly grounded and thus, as Michael suggested, it seems it is just creating another circuit leg that wasn’t considered as an option in the controller software. So, the fix that I’m going to have to do is swap the probe wires and only use the plate it seems. Not really a down side, a bit more convenient in my opinion but I wanted to make sure something else wasn’t wrong before I did it.

To test your theory just unplug the wire from the touch plate and put the magnet on it. It’s basically reversing the wiring without actually doing it. If the wiring is reversed you can still use the magnet as it will just be a second path back to the controller.

Did you hook up 3 wires to the spindle or all 4, the 4th one being the ground?

Not having my OF yet I have the spindle and been watching ton of videos.

I have been using mine that way for months now and love it especially after I forgot to remove the magnet once. That was not good!

From your description - where just using the magnet triggers the probe - it seems like your probe is wired “backward”. Flip the wires, and you’ll be good to go. You can leave the magnet off after switching - but it won’t hurt to leave it, it would just be attaching ground-to-ground.

1 Like

I had similar problems and found that depending on the collet I used determined the continuity…that’s not even a joke, it confused the hell out of me for a bit, but it seems that a certain collet I have determined which way it worked. I’m also runnings a G-penny spindle with a head of earthing throughout the frame/spindle and VFD.

Just use this topic to solve my probe problem, it was driving me crazy. Your test tip worked! My leads are miss wired.

1 Like