Mid Job Disconnect Problem (and potential solution)

HI all,

I’ve benefitted greatly in terms of troubleshooting with the help of the community here, the biggie being 2 dead spindles prior to switching to the Dewalt. I can’t speak more highly of the Inventables team and how they handled everything. It’s pretty rare to find a company so open and responsive. The X-Carve has proven a need at work, and they are getting me a big new ShopBot. It’s not here yet, so I continue to use the X-Carve, and I encountered a new problem I want to pass along with potential solutions. As we are switching to a new machine, I doubt I’ll go through the process of isolating which changes I made fixed it, so I’ll just throw everything out there. Maybe if the sell me the X-Carve I’ll look into it.

Two days ago I was getting constant disconnects. The steppers would just freeze and UGS would just add to the clock estimating finish time. I tried 3 different software versions and 10 or so cut attempts on 4 trashed pieces of stock. Each time it would fail at a different point. I also tried redoing the tool paths. Same problem.

However, this was the first time I used it with noticeable lack of humidity - chapped lips, stuff being attracted, getting little jolts throughout the day. I looked it up, and it’s a known problem in the Shapeoko community, and there are tons of anecdotal solutions. Mine is no more precise, but the changes worked for me. It was not a software or hardware problem in my case, just static electricity buildup causing some kind of fault as it earthed through the only way out, the USB connection. Or electrical noise…? Who knows. I think compounding this was that I have just started using HDU board, and it being plastic may have promoted a buildup of charge from being worked by the tool.

So it was end of week, and I had only one shot at a 3.5 hour cut, so I threw whatever I had of the kitchen sink at it. It was all ad hock git’r’dun with whatever was available. Here’s what I did:

  • Switched to a USB cable with two ferrite cores. I had tried this alone with no other changes, and while it cut much longer, it still failed ultimately. This is what leads me to believe it’s a surge through the USB connection.
  • Put an electrolytic capacitor across the Vout power supply to Vin motor driver board. I can shoot a photo next time I’m in if anyone is unclear. I just clipped the leads to the same length and put them in the terminal block of the power supply output along with the cable leads. The largest I had was a 470uF.
  • Moved the router plug to another outlet entirely.
  • Took a plug end and wired a lead only to the earth (do not attempt if you are at all unclear!) with the other end a tinned lead I could clip to. Plugged it into a socket.
  • When clamping the HDU to the spoil board, I lined the bottom with aluminum foil, leaving enough exposed to take a clip.
  • Using 3 alligator test leads: one from aluminum foil under clamped stock to earthed lead, another from Y carriage bolt to earthed lead, and yet another from Z carriage (router side) bolt to earthed lead.

First time, flawless cut. As I said, I have no idea which of these are responsible. Some better ESD protection could be built into the X-Carve without a lot of effort I think.

I hope this helps someone in the future!