Grounding issue affecting Touch Plate

General
1

Hello,
With the addition of the PWNCNC water cooled spindle and VFD I now have an issue that XYZ touch plate is now closing the loop once it is connected to the paindle head and not when the bit touches the plate, therefor rendering it inoperable.

The plate worked fine before and if the VFD and spindle is disconnected is works.

Any ideas how I can solve this?

Thanks.

2

Sounds like you need to switch the wires. Utilize the test to confirm.

https://support.pwncnc.com/kb/article/231-onefinity-touch-probe-issue-explained/

3

Hmm, from what I can see my scenario is as such:-

  • I’m using one probe, an Openbuilds XYZ touch plate.
  • The plate has LEDs which normally illuminate when connection is made.
  • As per the test you sent, if I touch the magnet to the body of the spindle the led illuminates straight away.
  • With the magnet attached to the spindle and illuminated if I then tap the plate to the bit the LEDs illuminate brighter with every tap. Indicating some sort of potential difference.
  • If I do the same test with the VFD unplugged nothing happens. ie no circuit is made.
  • if I attach the magnet to the frame of the machine the LEDs are fully bright.

So I can see the differences but I’m not sure how to fix it. I did try swapping the -ve and probe wires but that didn’t work.

Any idea how to correct this?

4

With the help of the Openbuilds forum I believe that I have isolated the earthing to be coming from the laptop power supply.

Thanks

1 Like
5

I had a response, but didn’t post it.

Glad you got it figured out, because all we got is swap the wires