I am not a fan of the LS THC, kind of like @Bigdaddy2166 and limit switches.
I have been fighting the THC for two years. For the most part I turn it off and play FireControl Whack-A-Mole with the “THC enabled but no THC points in program” pop ups.
The THC is however a necessary evil that you need to play nice when cutting materials that will warp.
So today was no different, first cut getting good voltage in the 140s, second cut OK, third the torch raises up and flames out because it is reading 70v. Turn off THC and the next cut is a whopping 4v.
I dropped a splash guard and clued into this potential problem.
Everyone always stated "Don’t coil your torch and work clamp cables, it will generate an EM field and screw everything up. Have Ferrite Chokes on your USB cable, both ends, maybe double up if needed (have not gone that far yet, but they are on both ends)
So I always have my cables laid out flat, running parallel, and run with it.
Evidently (and I may have been told this by older and wiser more experienced users here) proximity to the torch and work clamp, even though straight will cause issues.
I am not an EMI expert, so this is more of a question then a suggestion… but it seem to me your problem was here… where your USB gets intertwined between the Torch and the work clamp. My understanding is that the work clamp is the biggest contributor of EMI. Notice in your working solution you work clamp is isolated away from everything. I always try to keep my work clamp away from everything else.
That work clamp cable is the biggest issue I had. I was getting live voltage when the torch was idle. I could watch that voltage change as I moved the work clamp cable away from the other cables. I just kept moving cables until the live voltage went to zero.
Torch Fire isn’t an issue, but certainly keep the USB cable away from the Torch and Work Clamp cables!!!
Not sure what a CNC cable is… is this the cable that has the voltage monitoring? If yes, then this should be isolated from the Torch cables as well.
The torch cable has very high currents and high frequency components (not to be confused with High Frequency start) that will electromagnetically couple to any cable in its vicinity.
I started out with the rw45 then upgraded to a hypertherm 65.
The hypertherm is way more prone to issues than the rw45 as far as location of the wires. The USB cable get anywhere near the torch cable it will freeze everything up with the hypertherm.
Hope this fixes your issues. The THC has always been solid for me except for my own interference.
