[koendersav]

Hello, I have built a cnc table with a nvum as controlboard and a 1.5kw water-cooled spindle controlled by a VFD. Now I have the problem that when I turn on the spindle, my usb control board stops working. what could be the problem? I hope you can help me with this problem

[Formantjim]

Classic interference from the VFD there have been many threads covering this do a quick search. I had exactly similar issues with my Chinese VFD and the Easy Stepper needed to isolate the mains supply with an inline filter and move the ESS further away. Make sure the cable going to the spindle motor is shielded cable grounded at the VFD side and also make sure the VFD is grounded to the main supply.

[mactec54]

Hello, I have built a cnc table with a nvum as controlboard and a 1.5kw water-cooled spindle controlled by a VFD. Now I have the problem that when I turn on the spindle, my usb control board stops working. what could be the problem? I hope you can help me with this problem

Could be an easy fix but would depend on how you have the spindle and VFD Drive wired Post some photos and I will tell you what you need to do

[koendersav]

All the gear is connected to the same ground. without starting the VFD, the cnc machine works just fine but when i start the spindle, mach3 first tell that the usb device is reconnected and not working good at all

[mactec54]

All the gear is connected to the same ground. without starting the VFD, the cnc machine works just fine but when i start the spindle, mach3 first tell that the usb device is reconnected and not working good at all

Start By adding a Power Filter close to the VFD Drive input Power supply and connect R and T Terminals for the VFD Drive input power supply

Here is the EMI power filter I recommend for this

TDK RSEN-20-30

Is your USB cable double shielded 2 chokes can be better but 1 will work as well

Is you VFD Drive to Spindle cable shielded

Mounted in a plastic Box is not always a good idea, everything should be mounted on a metal Grounded Plate

[Valben]

Hi there, I have the exact same problem. Will the EMI filter solve the issue .? I have che checked all grounding connections and using a shielded spindle cable but the problem still persist.. As soon as I start the spindle, mach3 blips and message usb re- connected appear at the bottom of the screen, Thanks for help Valter

[RCaffin]

Bluntly, replace the USB device with an Ethernet Smooth Stepper.
The ethernet design can handle the RFI or interference; the USB design can NOT. End of story.

Been there, done that, never regretted the cost.

Cheers
Roger

[mactec54]

Hi there, I have the exact same problem. Will the EMI filter solve the issue .? I have che checked all grounding connections and using a shielded spindle cable but the problem still persist.. As soon as I start the spindle, mach3 blips and message usb re- connected appear at the bottom of the screen, Thanks for help Valter

Yes the EMI filter will do the job, you also have to Ground the shields correctly as well, I have more Grounding examples if you need more

The VFD to spindle Cable needs the Shield to be Grounded correctly at both ends

[mactec54]

Bluntly, replace the USB device with an Ethernet Smooth Stepper.
The ethernet design can handle the RFI or interference; the USB design can NOT. End of story.

Been there, done that, never regretted the cost.

Cheers
Roger

If everything is wired correctly the USB connections work without any problems

[RCaffin]

If everything is wired correctly the USB connections work without any problems
IF, IF, IF.
Forgive my disbelief: I tried and tried to eliminate the RFI, but I still had daily crashes. I switched from a USB SS to an ESS and never had a single problem again.
Biased, I am sure.

Cheers
Roger

[Valben]

Thanks guys :-)
I have tried an industrial EMI filter https://www.phoenixcontact.com/onlin...ary=usen&tab=1 but the problem persist.. I have connected the filter also to the PC supply and then to the CNC controller supply but the issue still there. unfortunately I only had 1 filter so I couldn't try having each power inputs through its own filter. Next step for me is to re-verify all grounding connections, shields bonding and then I will remove the spindle cable from the chain duct and route it in a metallic flexible conduit if I can find one.
I was also thinking about using an USB isolator but at this point it may be cheaper to get an ethernet cnc controller card as suggested by Roger.
Anyhow, your help is much appreciated, let's see how it goes.
Valter

[RCaffin]

USB isolator
I think I tried one of those. Didn't work.

Cheers
Roger

[mactec54]

Thanks guys :-)
I have tried an industrial EMI filter https://www.phoenixcontact.com/onlin...ary=usen&tab=1 but the problem persist.. I have connected the filter also to the PC supply and then to the CNC controller supply but the issue still there. unfortunately I only had 1 filter so I couldn't try having each power inputs through its own filter. Next step for me is to re-verify all grounding connections, shields bonding and then I will remove the spindle cable from the chain duct and route it in a metallic flexible conduit if I can find one.
I was also thinking about using an USB isolator but at this point it may be cheaper to get an ethernet cnc controller card as suggested by Roger.
Anyhow, your help is much appreciated, let's see how it goes.
Valter

What country do you live in as the Filter you have may not be suitable, it also needs to be placed as close as you can to the VFD Drive each item you are trying to protect needs it own EMI Filter ( Power supplies Etc.)

Ethernet is better but you should solve the noise problem

Is the VFD to spindle cable shielded and the shield Grounded at both ends as per the snip in post 8, if not that is a good starting point

USB isolator is not needed, and may not solve any problems, if your wiring is like the above cabinet then you need to tidy it up and Twist all the pairs of wires

Also check that the spindle 4th pin is Grounded in the spindle connector most are not and this needs to be corrected, you do this with a meter, continuity test Pin 4 to the spindle body

Are you using ( 1 ) power source ( supply ) for your whole machine

[mactec54]

Thanks guys :-)
I have tried an industrial EMI filter https://www.phoenixcontact.com/onlin...ary=usen&tab=1 but the problem persist.. I have connected the filter also to the PC supply and then to the CNC controller supply but the issue still there. unfortunately I only had 1 filter so I couldn't try having each power inputs through its own filter. Next step for me is to re-verify all grounding connections, shields bonding and then I will remove the spindle cable from the chain duct and route it in a metallic flexible conduit if I can find one.
I was also thinking about using an USB isolator but at this point it may be cheaper to get an ethernet cnc controller card as suggested by Roger.
Anyhow, your help is much appreciated, let's see how it goes.
Valter

The metallic flexible conduit is ok if it is not going to be moving up/down with the Z axis and spindle as it will fail quite quickly and it must be PVC coated, it can not be the straight metal type

VFD to Spindle must have a high flex rating IGUS is one of the best cable suppliers for this type of cable depending on your spindle Kw I can give you the cable spec's that will suit your spindle

[Valben]

Thanks guys, I have removed the spindle cable from the drag chain but the problem still there. This morning I have received the 2 TDK line filters ordered last week and will get them installed tonight. I couldn't find flexible conduit (EMI certified) at an acceptable price so if the filters doesn't solve the issue I may consider getting a CNC controller board with ethernet connection. cheers Valter

[asuratman]

Just easy question and to make sure, what size vfd power appropriate to motor power ? It is better to have slightly bigger VFD than motor or the same ? Say I have 1.5kw motor, it is better to have 1.5kw VFD or 2.2kw VFD ?

[mactec54]

Thanks guys, I have removed the spindle cable from the drag chain but the problem still there. This morning I have received the 2 TDK line filters ordered last week and will get them installed tonight. I couldn't find flexible conduit (EMI certified) at an acceptable price so if the filters doesn't solve the issue I may consider getting a CNC controller board with ethernet connection. cheers Valter

There is no point unless your VFD to Spindle Cable is Shielded and correctly terminated

Is your spindle Ground connected inside the spindle most are not and this needs to be fixed if it is not connected

The flexible conduit does not have to be EMI certified

The EMI filter needs to be as close as you can mount it to the VFD Drive input power supply

You have to twist the pairs of those power cables also

[Valben]

Allright so:
1) Installed EMI filters on power inlet of VFD and 24VD power supply power inlet. Twisted cable. Haven't installed a filter on the PC because the PC power supply has a built-in EMI filter.
2) The spindle body is grounded back via the connector.
3) Spindle cable shield connected to ground and removed from the drag chain (now not running parallel with the stepper motors cables)
4) Stepper motor cables shield connected to ground.
5) Replaced the USB cable with better quality with dual choke magnet.

The problem isn't solved, as soon as I start the spindle the PC blips and Mach3 indicates "USB device reconnected" and system becoming unstable.

I will do another test tonight replacing the PC with a laptop (I just need to install Mach3 on the laptop) and see if the problem is may be associated with the PC USB port.

After that I am short of ideas :-(
Valter

[Valben]

I have installed mach3 on a laptop and replaced the 2m long USB cable with a shorter (60cm) cable.
The CNC is somehow working and I was able to complete the first carving but with the machine stopping twice and loosing coordinates.
With the 2m long USB cable the USB coms drops every time I start the spindle and some time when I just power on the inverter.
I guess, I have a really noisy inverter unit (Huanyang) and this could be the reason why I can't get a reliable USB communication despite all the shielding and precautions.

As a (hopefully) final solution I have already ordered a new ethernet card.
in the mean time I will complete the final wiring of the control box and a separate metal box for the inverter so when the new ethernet board arrives I will just need to replace it and set-up coms.

Cheers
Valter

[Valben]

CNC Control Panel almost completed, hopefully using a metal enclosure I will get rid of the EMI problem...… and if not, I will replace the USB controller with an Ethernet Controller.