Lincoln FlexCut 80 frequent lost cut

[jlasater]

In running my first project which involved cutting 14 trapezoid shapes about 15 inches wide, I had frequent "Cut lost..." messages in the Torchmate VMD with the plasma torch shutting off. I was running about 90psi on the FC80 air gauge when actually cutting. The plate had some surface rust but I cleaned that off for the most part with ScotchBrite. The ground clamp was very rusty, so I replaced it and cut back the ground cable until I saw no corrosion on the copper inside, and sealed the joint with adhesive-lined heatshrink tubing. I did notice that when the problem happened, it was usually on the Y axis cut running right-to-left. The Y axis left-to-right cut on the bottom surface rarely had the issue. I have a basic regulator/water filter inline right now, but have a much better one on order. Likewise I don't have any extra consumables at this time (none came with the used Torchmate 4400) but have a full set on order from Lincoln.

I tried running the cut speed from 120ipm down to 60, but it made little difference.

You can see progress here, and a number of the incomplete parts:



Now...I'll confess that I modified the one 80A nozzle that came with the machine. The problem I ran into repeatedly was not being able to get the PiP feature on the FC80 to be happy. If I left the nozzle out (obviously I wouldn't run it this way), PiP was happy, but put the nozzle back in and I couldn't get the PiP light to go out. So...being a hobby machinist, I took a couple thousandths off the flange on the nozzle, put it back in, and problem solved. This may well have messed up the electrode clearances...I just wanted to get the machine cutting! (I was being impatient, yes you're welcome to laugh at my expense.)

All the consumables will be replaced as soon as parts arrive, and I definitely won't be modifying anything. If the torch has mechanical issues (it came from a school environment and may have been crashed repeatedly for all I know), I may have to send it in for repairs, if Lincoln fixes that sort of thing. I hope so on an $1100 part.

Short vid of it running. When cutting more of the same part on the same sheet, there were frequent stops for "Cut lost..."
https://www.youtube.com/watch?v=C878dwK8JXI

[weldguy]

I am curious if you notice the yellow LED second from the bottom on the face of the FC80 light up when this happens?

[jlasater]

I don't know. I'll set up a couple long cuts on the scrap area that's left and keep an eye on it and the pressure.