Cnc randomly disconnected

I have a lot of trouble with my CNC since 1-2 months. I have my cnc since last summer without major issue. But now I have many issues of disconnection.

I change my wasteboard and add 100 inserts nuts. I already have 7 t-track between my mdf wasteboard board.

Since this time my cnc stop working after short time. Between 30 secondes to 3 minutes. It never stop at the same place. Each time I have to disconnect my usb cable to be able to restart the cnc

It happen with UGS, CNCjs and gSender.

I grounded all my dust collector system, hoses, pipe and the dust collector motor is ground to the lightning rods. It work for 2-3 days without issue but today It came back.

I grounded the cnc frame (both X axis, Y axis, z axis) with crocodile clips all connected to my electric outlet ground.

The floor of my shop is all in painted plywood and concrete slab under this.

What can I do more? Seriously I’m pissed off

I didn’t succeed any cutting job without disconnection. I scrapt a lot of wood because the lost communication.

Help needed please

@GuillC I really do feel your pain, Guillaume. I was doing well for some months, then all of a sudden, every job froze. Now, I’ve been good again for a couple of weeks.

This has been discussed many times on this forum, so pretty much everything I say here has been said before. However, here goes:

  1. Try a job without your dust collection running. If you can run consistently, you likely still have some grounding issues.

  2. If that does not fix things, make sure that you turn off ALL power saving features in Windows. Be sure to include the USB port power saving.

  3. If that does not fix things, replace the USB cable. Make sure that the replacement has good ferrite chokes.

  4. Ground your router.

If none of these work, post again, although I’m fast running out of ideas. :slightly_frowning_face:

1 Like
  1. I try to run without dust collection = same issue, maybe it can run little more time before stall.
  2. I’ll try, but in my mind it can happen if it’s a big carving job like 1-2-3 hours. But this issue happen after less than one minute.
  3. I change my USB cable with my printer cable (maybe less quality but…) the cable didn’t have ferrite chockes. It’s not expensive to try…

after all of that I don’t know what to do anymore…

On January my Arduino was dead and I changed it. Could this have damaged the controler board when the Arduino is dead.

There is a power input in the Arduino Board. Connecting this to a power supply may reduce current interference ?

@GuillC Did the problem start after you changed out the arduino?

Did you flash the arduino with the Long Mill firmware from the Sienci site?

You may want to take a look here:

https://wiki.shapeoko.com/index.php/Electronics#USB_Disconnection

The list of possible issue is quite overwhelming, I think. However, there is a lot of good information on that page.

I can’t help on the benefit of connecting the arduino to its own power supply. It should be able to do its job with the 5V coming in from the USB. Here is some info on doing it:

https://forum.arduino.cc/index.php?topic=357074.0

My Arduino board is a brand new board from Sienci (warranty claim) it was updated.

The problem start after I change my mdf wasteboard and install threaded insert nuts in and flatten it. At this time I caught lot of static each time I touched my cnc rails. After grounding my dust collector and my cnc I didn’t caught static anymore. But still have disconnection each job

I will read your website link. Thanks

Any chance you added a USB bridge to your system? Maybe a confused com port issue if you did?

Ok I got it.

Since beginning of my issue, I put my laptop in my cabinet to reduce dust on. I connect it with displayport to a hub switch - DVI cable to a Monitor on the wall. My usb cable between laptop and controller go left to right under my table.

I think I have static interference under my table.

I put my laptop on a table side to my cnc table and no more problem dust connector on or off.

So I wish to find solutions to this. Because I want to put my laptop away from dust.

@GuillC That’s interesting, Guillaume. When you moved the laptop to the table, did you change where you plug it in, or anything else? It’s unlikely, I think, that some sort of static charge is being generated by the laptop when it is in the cabinet and that charge is passing through all that wood to affect the Mill controller. That said, where is your Mill controller?

Try running without the bridge and see if that changes anything. Also, I had less bridge issues with the new gsender software.

@msparks916 What is a USB bridge, Michael?

Also called a USB hub. It allows people with systems like laptops that have only one USB port to add 4 ports connect to 1 available port on the LT so they can run more than one USB device, which can sometimes cause some COM ghosts.

@msparks916 Tks, Michael. I know what a hub is. I had never heard it called a bridge before. Learn something new every day. I didn’t see a hub in any of Guillaume’s pics, but it’s worth considering.

@GuillC As Michael points out, if you are using a USB hub, it will be worth removing it to see if your issues go away. This will be especially true if it is not a powered hub. It should not cause a problem if it is powered. In fact, one of the solutions put forward on the Shapeoko forum for freezing is to use a powered USB hub.

1 Like