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.
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 
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.
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.
-Alex
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