Long Mill 30x30 disconecting from computer

Hello fellow CNC’ers
I’ve now had my Lon Mill for about 3 months and everything has been going relatively well other than operator learning errors.
Recently I have been having an issue with the unit disconnecting from the computer for no apparent reason.
I am wondering if anyone else has had this issue and would anyone have some helpful tips you can pass along
Thanks in advance,

@Sparky-18 Hey Mike, WELCOME to the forum. There is a great group of folks here that will be able to assist you. You could always get in touch with Technical Support at Sienci as well. They will definitely assist you.

I don’t have an answer for your problem, heck I don’t even have my MK2 here yet. But I do ask that when you get an answer that fixes your problem, to kindly post the solution here. It would help greenhorns like me when I have the same problem.

Again, welcome and be safe!


I had the same problem and I found that the problem was in the motherboard of my computer. Used a different computer and haven’t had the problem since.

@Sparky-18 Welcome the group, Mike.

I suggest that you do a search on this forum for “freeze”. You’ll find many have had your problem (me included) and you’ll read of the many solutions tried. Some have worked well, others not so much.

I have gone many months without any freezes, but have had 3 in the last few days. I moved my room humidifier down to my basement shop and had none since. Coincidence? Maybe, but you can read many informed sources on the net that say that arduinos and grbl hate static build up, and static build up is at its worst in dry air conditions.

That said, there are also “experts” who say that I am all wet - pun intended. Unfortunately, there are no easy answers, but you’ll find a lot of information here from people who have actually had your problem and solved it.

Good luck. Report back on your results, please.

Thanks to ALL that responded
All you points are well taken. I am confident a resolution to the problem will be found.

Cheers everyone

First thing I would try and I t may sound stupid but get a new cable to plug in. Never know they can go bad for what ever reason. Vibration can cause all kinds of stupid things to happen. I would try that first.

Ok so I have had this problem more than a handful of times. I have narrowed it down and have found a fix to my problems with this. I would not buy a new computer like someone said before trying these things first. Power your USB outlet and plug your mouse in that powered outlet also. I bought a 4 port powered outlet on Amazon, worked great. You can turn off the other ports your not using. Next you must have your windows up to date no matter what before you carve. Next, I purchased the blue usb cable and found it to be defective so toss it. Use the one you purchase from Amazon and another higher end cable from your controller to your powered port. The only disconnection issues I now have are when I’m pushing my routers feed rate higher than it can keep up. If my bit is dull, I will most likely have to reduce the feed rate so my sender isn’t faulting when my machine can’t keep up. After doing these things you shouldn’t have an issue. Also as a side note, when your router starts jumping or sputtering through the wood instead of a smooth cut, you are going too fast and need a new bit or slow feed rate down.
Good luck and keep your rails clean!

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