Control box wont remain connected to my pc

I’m trying to run my first cut with the crossfirepro, but the machine and the THC both keep disconnecting from my pc as soon as I load a g code. If I connect it after reopening fire control it will remain connected and I can operate it manually; but as soon as I load a file both devices keep disconnecting and reconnecting over and over again until I restart the program and reconnect the USB cable. The app also stops responding quite a bit until I restart it. I’m thinking it might be something with my pc, but most other usb devices I use will remain connected.

There are two main reasons that the PC will lose its USB connection to another device. One, which has been mentioned several times in the forum, is electrical interference from the Plasma Cutter when the torch is on and the USB cable is insufficiently shielded. It doesn’t sound like this is your problem as you say it disconnects as soon as you load g-code (before the torch is fired).

The second reason is if the USB port on the computer is not able to handle the electrical load of the CrossFire controller (along with the stepper drive and torch relay interfaces). In this case the only solutions are to switch to a higher power USB port on the PC. Theoretically using a USB hub that repowers the USB power could also solve this problem, but that opens up a new opportunity for interference to interrupt the USB signals. I haven’t tried this approach but have considered it.

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Make sure all of the drivers for your mobo (motherboard) are the latest as released from the manufacturer not Microsoft or windows update. Also make sure your bios is up to date.

If you do use a powered usb hub be careful i have heard of powered ones frying laptops… but not experienced this first hand.

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Wow, I hadn’t heard of this before but just DAGS it to follow up. Sure enough, some cheap powered hubs will actually supply power to the host device (AKA PC). That’s amazing and dangerous! Thanks for the head’s up. The moral of the story is: Always buy quality brands for your interface!


What is your recommended protector for the USB connection when I use the laptop stand?

use the ferrite choke what was provided. if you didn’t receive one then email Langmuir and they’ll send one out to you. also, if your laptop/desktop has a 3 prong power cable, meaning it had a ground prong, use a 3 prong to 2 prong adapter to eliminate the ground.

I tried using the ferrite choke the machine came with, and I downloaded some updates from lenova for windows 10. The device stays connected without the control box turned on, and even with the plasma cutter turned on; but once I turn on the controller it starts disconnecting. My pc (thinkpad e540 model 20c6008sus) was updated to windows 10 from windows 7, which might have reduced its performance, but the pc is well compatible for windows 10. I also get some errors that keep failing to send when I try to report them.