I have been chasing EMI and ground loop issues on my Crossfire Pro with Primeweld CUT60 for years. To be clear, I do not believe this is a Langmuir problem, the Primeweld CUT60 is known to be a noisy girl and was removed from their recommendations list. But that said, the Crossfire Pro electronics were not designed to have robust protection against such cutters that throw off a lot of noise.
What were my symptoms? The most common was simply disconnections to the electronics during a cut. But it gets worse, it has smoked laptop USB ports, cooked laptop speakers and touchscreen digitizer, released the magic smoke from resistors inside VIM modules, and caused problem after problem. THC signals were unreliable during live fire, and the voltage signal would stay floating high (very slowly lowering over time) even after the touch shut off. The problems were substantially worse when THC was used, regardless of whether I was using raw or divided. With THC wiring disconnected the issues were far less common, but not zero. Yes to all the usual troubleshooting, I removed PC power ground, yes there was absolutely no continuity between the controls chassis (i.e. USB ground) and the table, etc.
I have finally solved it once and for all using signal isolation modules for both the IHS and THC.
I now have zero issues.
I get an absolutely rock solid THC voltage signal, every time, every cut.
Isolation IS the key! The original design breaks several engineering design guidelines and literally begs for failure.
I have an OG Crossfire and added my own THC, IHS, Z Axis, and replaced the enclosure with a plastic NEMA 4 enclosure. The THC is the THC3T-02 which has an isolation power supply and, more importantly, an isolation amplifier as you have added to yours. I’ve never had a noise problem with mine.
This is brilliant! Thank you, I plan to build one for my setup. (I have a Cut 60 as well…)
The link to the 0.5v to 0.5v isolation for THC appears to have expired. I can find a similar unit on Amazon but can’t quite find one with a stated 0-5v output. I can find a 0-10v output easily however. Do you imagine that would work? Could you provide any other info on yours so I can hunt one down? Thanks again!
