Hi,

My father and me we have built a rustic CNC and it does some good work.
I will attach to this message examples of works and machine pictures. As you will see I had not discovered this forum before building it and we have certainly done some theoretical mistakes.
The second will certainly be better and cheaper.

We use an Arduino-grbl-UGS system. The parameters will be accessible at the end of this post.

Basically, the CNC works but sometimes it stops.
On the screen OFFLINE (black) appear instead of RUN (green) and the CNC stops moving.
The strange thing is that the little orange logo showing connection is still orange when this happens like if we were still connected. And it's impossible to disconnect/reconnect using the logo.
We have to reconnect using the setup wizard procedure and a homing.
It takes a lot of time and as it happens totally randomly (sometimes after 5 seconds sometimes after 12 hours straight without problems we have to constantly look at it whereas we could do other things during the time it works.

We have suspected many different problems :
-connection problems - solved by replacing connectors, using weld instead of bolts.
-electromagnetic problems - solved by replacing the cable with shielded cables for the spindles and the motors. And we manually shied the USB cable waiting for a good one from amazon. We also tried to make a metallic shield in front of the computer with no effect.
-static electricity - solved by connecting pretty much everything to earth we even separate the dust collector from the CNC to see if it changed something.

We certainly also have tried other things I forgot but now we start to be out of ideas and we look to the internet to find the solution.
Sadly I haven't been able to find a post with this type of disconnection.

Did some of you already have this problem?
Could you provide me some idea or link where I could find a solution?

I will be happy to share more information/photos/data if necessary.