# Grounding a Chinese spindle



## Gary Davis (May 15, 2019)

I am at the point in my homebuilt CNC project where I am preparing to wire the Chinese spindle, watched a number of videos concerning the lack of ground connection. All the spindles I have seen in the videos had 4 small screws holding the male connector to the top of the spindle. Of course mine does not use the plate with 4 screws. I have removed the 4 screw around the top section of my spindle and have tried to twist that section in either direction to get access to the internal wiring. Have not used force as I do not want to do damage.
Any suggestions as how to get to the wiring would be appreciated?


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## PhilBa (Sep 25, 2014)

Does the barrel of the connector on the spindle (center top of the spindle in your picture) have conductivity to the metal case of the spindle? I'd bet it does so you could use a shielded cable from your VFD to get a ground connection. If you don't have a shielded cable, you might be able to get a ring terminal that goes over the the top of the barrel and use that for a ground wire run back to the VFD. They make them with up to 3/4" ID rings.


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## Gary Davis (May 15, 2019)

In checking continuity with my multi-meter I only get ground by touching the threaded connector and either water connection. 

No other combination of touching case, spindle, etc,,I just heard from someone that says that upper black portion is held tight by o-rings and it will come off. I plan to check it in the morning.

Thanks for the response.


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## difalkner (Jan 3, 2012)

You have to separate it at the black phenolic piece and the body of the spindle, Gary. It may be a bit tough to break loose but I got mine off by tapping with a wooden mallet. You can see in the photo that there are O-rings and a shoulder. I changed my connector out for an Amphenol with ground and you can see how I ran the ground wire in the photos below.

























David


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## BalloonEngineer (Mar 27, 2009)

The top of mine was metal.


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## difalkner (Jan 3, 2012)

BalloonEngineer said:


> The top of mine was metal.


My bad, Richard. The top of mine is aluminum, not phenolic. It's been a while since I did that so I glanced at the photo and typed 'phenolic' without even thinking about it. I should have remembered because I drilled and tapped it for the grounding screw and had to drill for the Amphenol mounting screws. Oh, well... :wink:

David


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## Pro4824 (Oct 17, 2015)

So what do the Chinese have against ground wires???
When I bought mine, I asked if the ground wire was connected and they said yes.... Oh well, it's grounded now. 🙂


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## Gary Davis (May 15, 2019)

Thank yous to David, Richard and Joe comments and pictures greatly appreciated!


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## mkoukkgou333 (Feb 21, 2020)

i have go though the wholesale post carefullly.....


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## erniehatt (Aug 19, 2020)

Gary Davis said:


> I am at the point in my homebuilt CNC project where I am preparing to wire the Chinese spindle, watched a number of videos concerning the lack of ground connection. All the spindles I have seen in the videos had 4 small screws holding the male connector to the top of the spindle. Of course mine does not use the plate with 4 screws. I have removed the 4 screw around the top section of my spindle and have tried to twist that section in either direction to get access to the internal wiring. Have not used force as I do not want to do damage.
> Any suggestions as how to get to the wiring would be appreciated?


Hi, when I changed to a 2.2kw spindle, I wired it all up using a four wire cable, then ran an extra wire from the groung connection out to the piece that tightens round the cable, My spindle is now grounded.


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## gmedwards (Oct 12, 2018)

Gary, before you put the top back on, I suggest you get some new O-rings and replace the originals. Last thing you want is a water leak into the internals.


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