New Issue...eventually I'll figure this out

Ok, So I’ve had my Crossfire Pro without THC, for a few months (July 20th) now…but only made a couple test cuts…that lasted a min or two. Now an issue I’m having is I just loaded up a file with a 5x15 sign, and about 1/3 to 1/2 though my pc has froze or shut down completely. I’m not sure if this is a Software Problem or Hardware Problem, or interference/EMI problem. Plasma Cutter is a Primeweld Cut 60 that I purchased this July 7th. I unfortunately purchased it before I read of some of the issues people had with interference so not sure if it’s related to the issue I’m having. Pc if spec are needed is Desktop Intel i7-4790K 4.00 GHz Quad Processor, MSI Z87-G41 Motherboard, G.SKILL Ripjaws X Series 16GB Ram, EVGA GeForce GTX 550 Ti, 1TB WD hard drive running Windows 10.

Are you hooked up using raw voltage or divided voltage?

I would hook directly to raw voltage on your plasma cutter.

I’m using it without THC so I don’t have it hooked up any voltage detection…though I’m about to order the THC.

Are you using the USB cable that was supplied by langmuir?

How much distance do you have between your computer and your plasma cutter?

Try getting some ferrite chokes and adding them to your cable. Add one with two loops nearest to the control box like this.


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I’m using the USB cable that came with it…the Computer is probably 3ft feet away, and about 2 foot above the plasma table. Tomorrow I’m going to move the Plasma cutter even further away, and I can move the the computer about another foot over…so I’m going to try that. Also I have Firecontrol on my laptop…so all else fails, just prefer desktop over laptop.

Ok, that might be a good thing to try too…and I probably have some laying in one of my parts bins…if not Amazon…sure I can have them here in a day.

Is your laptop running on battery power or is it plugged into the charger?

So early few test cuts, I did with my laptop, but recently I put my old desktop…and the only thing I’ve cut with the desktop was a couple of bottle openers…but in the past with laptop I had it powered by outlet but with a full battery if needed.

Try using your laptop on battery power. Sometimes your computer sharing a ground with the control box can cause interference. If you need to plug into the wall try using a ground adapter.


will try that that tomorrow

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Ok, not sure what is going on with the desktop computer hooked up to my Crossfire Pro, but my laptop works fine without crashing…so for now, laptop it is.


If your desktop power supply has a grounded chord that is what is causing the interference. If you use your desktop or your laptop while plugged into the wall, use a ground adapter like the one shown below.

Ground loops are voodoo I really don’t understand but isolating your computer from the ground your control box uses with a ground adapter should “solve” the issue.

You could also try a USB isolator… if you reach out to Langmuir, they will send you one.

@TomWS or @Bigdaddy2166 may have a better explanation.


I do not have an ‘explanation’ that explains why you SHOULD put this thing on your laptop power cord, because I don’t think you should. However, I do have an ‘explanation’ on why you NEED to do this on these systems, but, since my ‘explanation’ isn’t ‘pretty’, I’ll keep it to myself.


Hey Tom, I was thinking you could explain the voodoo part of ground loops… not justifying using a ground adapter. I know you’re not a big fan of the “fix”

The ground prong on the laptop power supply is making a ground connection through your electrical service ground. Via the ground plug on the Langmuir control box. Ground loop…
I agree with TomWS, the whole idea of disconnecting ground protection to sensitive electrical components is craziness. It will fix your problem if in fact thats it.


I have a Cut60 that’s almost 3 yrs old and I feel it has not caused me any problems. I have only been using my CNC table for a few months, but it’s going pretty well. I believe my freeze ups have been caused by my old Dell laptop.

I have taken several precautions though: I placed a 1/4" piece of hard plastic between my control box (CPU) and the frame of the table when I mounted it; I don’t have my laptop charger plugged in when cutting; I have a magnetic ground attached directly to the work piece; I wired directly to raw voltage; I split a piece of thick rubber hose and placed it around my cutter cable running up the support pole that routes the Z-axis and torch wires. They area also on opposite sides of the support pole.

Just get a computer that doesn’t require the ground. Charge via usb c, or use a little stick pc.

I have this plugged into a 40 inch tv and a Bluetooth keyboard in the garage. Works great.

MeLE PCG02 Fanless Mini PC Stick Windows 11 Pro Celeron J4125 8GB 128GB Micro Desktop Computer Stick Support HDMI 4K 60Hz Wi-Fi Ethernet Work on Business Office Industrial IOT Media Video


I agree with BrownFox. This is what my table uses. It will even run Fusion 360. Less than $300 and very powerful.

Just download Google drive and all your files will be there when you open up FireControl.


Care to share the make/model? I’ve been pricing Intel NUC type platforms but haven’t decided on one. I want to do what you’ve done and piggy back one on a touch screen monitor that I also need to buy.