Revisiting my disconnect issues caused by 3 phase spindle. /vfd

I had quite the thread going on this before and I decided to purchase a cheap tablet to leave unplugged while cutting to get around the issue.

Well the limited battery life has become an issue forcing me to revisit. This is going to be a bit of a read.

So issue is that as soon as my spindle is turned on I have a disconnect. It’s nearly instantaneous.

I have an hf vfd and a 2.2kw water cooled spindle from amazon. A xxl shipped in Jan 2019. I have an hdz also.

This will happen to any computer while plugged in to an outlet. I have tried 2 laptops, 2 desktops, and 1 tablet.

I’m going to rule out a usb cable. I have tried 6 different cables. Shielded , ferrite cores, 3 foot to 1 foot it doesn’t matter.

It’s not a grounding issue. I have ran grounds from an electrical box to the controller and each of the rails. The spindle is also grounded. Yes the ground is connected inside the spindle. I have verified grounds at both the mounting bolts and the usb shield on the board.

It’s not a shop electrical issue. Not a ground loop. Everything is plugged into its own circuit. I’ve checked the ground rod and all ground connections in the house.

I have ferrite cores on all the wires going into and out of the vfd. Also have more cores on the shielded cable going to the spindle.

I have a power filter on the power feed to the vfd.

Things I have not tried:
A usb isolator.
A powered usb hub
My vfd to spindle cable is ran through my wire chains. I haven’t tried to remove it yet.
I have not removed the rpm command wires from the board to the vfd and tried to command it manually.

So who has something to add?

One bit of a back story is I had a vfd failure that put enough voltage to the rpm command wires that it cause sparks at the board connection. So in my mind I may have a board issue.

You have clearly done your homework (and more), I don’t have anything to add that you did not mention (yes, I would try separating the VFD cabling from the USB cable, and using a USB isolator), but here’s a wild idea if you are willing to get a little nerdy:
Get an Arduino Uno (the ones that have a USB type B connector like the Shapeoko controller), flash GRBL 1.1 on it (easier than it sounds), then unplug the USB cable at the Shapeoko controller, and plug the Uno there instead. Leave the Shapeoko turned off, use CNCjs or USG or another G-code sender (but not CM, it can tell a Shapeoko from a generic Arduino board), connect to the Uno and and see if you still get disconnects upon turning on the VFD. If not => that would be one more reason to replace your controller board. I can’t remember from the first thread if you had contacted support about the semi-fried controller ?


Might also be worth swapping out the Shapoko power brick, bad PSU can contribute quite a bit, or even run the Shapoko on battery.

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I never contacted support about the board. It functions fully. Sparks were from the wire connections at the bitrunner connector.

Another thing.

My controller and numb vfd are powered on by a single 3 pole relay. Which is controlled by a magnetic paddle switch from a router table. I’m curious if I could be getting interference there. I wouldn’t think so because it’s before the transformer. I could just move the controller plug to a different circuit for testing.

Sorry if it’s weird that I’m pointing out all the stuff I need to try. Just find it helpful to get others opinions at this point

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Please contact — at a minimum we can work out getting a USB Isolator to you.

How is your spindle power cable routed, and what kind of wire are you using for it? (Sorry if you mentioned this already, on my phone and I can check the OP while commenting.)

I used to get real bad disconnects with the standard router, and I was super afraid that upgrading to a 2.2kw would be a nightmare. But I used some heavy duty shielded wire to run to the VFC, and I rout that cable from the spindle up to the ceiling in order to keep it as far away from the rest of the wiring as possible. Haven’t had any issues yet (knock on exotic hardwood).

Separating the spindle/router power from the rest of the wiring seems to have been the magic bullet for me, along with the USB isolator I got from the Carbide team.

Here’s the wire I am using:


That’s the good stuff, drain wire, braid and full foil shield.

Hey @WillAdams, what USB Isolator do you (and/or Carbide 3D) recommend?

I’ve been considering a pro-active step of adding one “just in case”, even though the (very rare) problems I have had has been due to a loose usb connection. I’m assuming there is no downside to using one, and if I’m about to remove the USB cable for some gentle bending (to make it fit tighter) I was thinking about adding one of these USB Isolators.

We recommend:



Also note the opensource:

which was mentioned at:

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