VFD interference problem

[eurikain]

What if I buy an ethernet smooth stepper as you told me a few weeks back ? ESS smooth stepper ? That would prevent the ground loop going back to the PC since it's ethernet based.

[komatias]

What if I buy an ethernet smooth stepper as you told me a few weeks back ? ESS smooth stepper ? That would prevent the ground loop going back to the PC since it's ethernet based.

The Ess will help some but the ground loop will always cause issues. Have you powered the Bob with the USB cable? If so then have you tried to disconnect the cable and use a different 5v source?

[eurikain]

Nope, the BOB is powered only using a 5VDC external power supply. Weird that I'm the only person with this issue.. I've got the exact same board as the one you sell on your website. Typical cheap Chinese BOB. But it works for everyone else.. why not for me :'( ?

I have a PCI parallel port expansion board. It might be interesting to install it and test if it improves or fixes the ground loop. It might be the native parallel port of my PC that's not working properly. I'll give it a try on Thursday.

[JAZZCNC]

The Ess will help some but the ground loop will always cause issues.

It will with the ESS which think pulls Gnd from PC like the BOB but not with IP-M which is isolated from PC and pulls Gnd to Mains Earth. It also uses Differential signals with isolated Inputs which is why it's so very good at not being affected by noise.

That said you still need to be 100% sure it is the BOB and not some other cause.?

[Clive S]

Have you tried getting rid of the ribbon cable and plugging the pp lead straight in to the BOB

[eurikain]

Jazz, I'm not sure to understand what you are saying... will the ESS fix the issue IF it is a ground loop going to the PC ?

I have tried getting rid of the ribbon cable. Same problem, though I had disconnected the X axis motors because I didn't want to twist the gantry. But then it was a little more difficult to hear the noise but it was still there. I will do some more tests on Thursday, I'll connect everything back together to get the maximum noise, then disconnect the DB25 cable and see if that stops it. I'll let you guys know ASAP.

[komatias]

Any ethernet socket is galvanically isolated on both sides. So it will not pass direct currently to and from the computer. The ground loop will then not be present. But if there is an issue in the wiring then it may cause issues nonetheless.

[eurikain]

Yes, but the ground loop could still flow through the cable from the BOB to the ESS, or not ?

[Clive S]

But then it was a little more difficult to hear the noise but it was still there

What is noise you are hearing? You can't hear EMF

[JAZZCNC]

Jazz, I'm not sure to understand what you are saying... will the ESS fix the issue IF it is a ground loop going to the PC ?

I have tried getting rid of the ribbon cable. Same problem, though I had disconnected the X axis motors because I didn't want to twist the gantry. But then it was a little more difficult to hear the noise but it was still there. I will do some more tests on Thursday, I'll connect everything back together to get the maximum noise, then disconnect the DB25 cable and see if that stops it. I'll let you guys know ASAP.

In theory yes it should but like been said depends if this really is the source of trouble.? That said I'd still change the BOB because it's clearly not very good because shouldn't happen even with parallel port.

Now like Clive ask's What Noise.?

I think you miss under stand what is meant by Noise. It's not audible so if your hearing any noise that's something else.?
If your using AM Digital drives then I suspect it's because you haven't tuned them. Or what your hearing is the current reduction in the drive working while motors are stood still. This will make an Hissing sound.

Electrical noise or EMF is a Silent Killer.!!

Very difficult to help from distance when it comes to noise. All you can do is be meticulous with wiring and gnding. Ensure separation between signal and power cables.
If still present then fit EMF Filters etc.

If still present then start back tracking.