Surprise benefit to grounding your spindle

I wired my spindle with a proper shielded 4-conductor cable. The ground wire is attached to the casing of the spindle. The other end shares a common ground with the VFD and Onefinity controller.

I found a surprise benefit is that if I forget to attach the probe magnet to the collet, the probe still registers through ground when touched and works normally- saving the tools from any damage.

(It’s scary how many times I’ve forgotten to attach the magnet already!).


I have religiously tested it prior to hitting probe by holding it to the bit by hand… The day I forget it the day I can write my “I drove my rough probe into my waste board and turned a bit into a paperclip” post. I am sure it will be a brand new fancy boy when I do it to.

I’m with you. So simple, but why don’t I remember. I have a nice cut in an aluminum threaded table because I forgot. Now, as I have that mistake glaring at me during job set-up I don’t forget as much.

It only took me one time of busting a brand new, never used ball nose to never ever forget to attach the magnet.

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Just out of curiosity , would it be possible to ground the Makita router and get the same result?

Thanks ! will give that a try, I just broke my magnet wire today maybe I wont need it :slight_smile:

Oddly enough this seems like a good way to test if you have ceramic bearings in your spindle. The path to ground without the mag ground would need to pass through the bearings.

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The latest firmware asks the user to touch the TP to the bit then it disapears. This is also how Easel (X-Carve) does it, it is an awesome way to ensure you do not forget to connect everything which as we know ends up with a cracked $$ Bit.

Check it out, I think you’s like it.


Yes thanks Muddyfeet! i followed you. got rod of my old banana plug wire and instead connected my old magnet wire to the banana plug and then to h ty e touch plate (effectively not using anymore the old banana plug wire). wired up my spindle ground wire to my OF and now it can probe with only the touch plate :slight_smile: