Pictures of the warped sheet would help, as well as the gcode run, how you generated the gcode, and your THC settings (if different from default). Remember the default turns off the THC if speed drops below 85%. So if you had some small holes you were cutting and set a speed 60% of normal, the THC would be off.
If you are computer savvy run OBS or any other screen capture app to record Firecontrol, so you can replay what’s happening with THC. Hopefully they’ll add logging soon.
Thanks.
The warp in the sheet was just a little tweak from having the work clamp lifting it up a bit. I was doing it pretty much to test it.
Here’s the G-Code, which I generated with sheet cam. I can’t find any settings in sheet cam that appear to affect THC directly… I did not change the torch speed at all. I did try setting the nominal voltage to what HT book specs show in fire control to see if that affected THC but still nothing.
I need to switch to inches to be able to read the pierce heights and stuff better also
(SheetCam - FireControl Post v1.5)
G90 G94
G17
G21 (Units: Metric)
H0
G0 X762.5473 Y113.4312
G92 Z0.
G38.2 Z-127.0 F2540.0
G92 Z0.0
G0 Z5.08
G38.2 Z-127.0 F254.0
G92 Z0.0
G0 Z0.508 (IHS Backlash)
G92 Z0.0
G0 Z3.81 (Pierce Height)
M3
G4 P0.2
G1 Z1.524 F1524.0 (Cut Height)
H1
G2 X756.8428 Y112.7307 I-3.2025 J2.502 F5715.0
G1 X756.8161 Y112.7506
G3 X729.1301 Y121.0872 I-26.2629 J-37.0784
G3 X691.3033 Y102.6466 I-0.6837 J-46.6144
G3 X682.9296 Y111.2647 I-35.2206 J-25.8446
G1 X682.9158 Y111.2752
G3 X640.8473 Y119.66 I-29.9234 J-40.4064
G3 X620.4417 Y107.4474 I7.1194 J-35.0492
G1 X620.4149 Y107.413
G3 X614.6991 Y83.5652 I25.654 J-18.7576
G3 X626.5498 Y55.3017 I62.8125 J9.7207
G3 X644.6428 Y36.8982 I65.9036 J46.6964
G3 X690.9957 Y9.354 I154.5245 J207.2676
G3 X691.5917 Y9.3544 I0.2976 J0.646
G3 X737.3077 Y36.4049 I-110.2256 J238.4401
G3 X756.0402 Y55.3062 I-49.1169 J67.4116
G3 X758.3429 Y58.758 I-71.1086 J49.9311
G3 X768.1837 Y87.3249 I-48.233 J32.5939
G3 X756.8428 Y112.7307 I-29.6172 J2.0133
G1 X756.8161 Y112.7506
G3 X754.1917 Y114.4764 I-26.2629 J-37.0784
G2 X752.8352 Y120.0614 I2.1143 J3.4707
H0
M5
G0 Z25.4
M5 M30
(PS5715)
The gcode looks fine with respect to the THC, THC should be on for the cut.
Only thing is your pierce delay is only 0.2s, which may be a bit short as there is currently a discrepancy between how Langmuir and Hypertherm measure pierce delay, resulting in book Hypertherm values being too short. The other thing to remember is if you are using Smart Voltage the THC waits 0.25" (default) before measuring then another 0.25" to gather readings before making adjustments. See the docs
If you could record the screen and the cutter you will get a better idea of what is happening.
Thank you thank you! You actually answered another question I had. The pierce delay is causing an issue for me on subsequent pierces. I was advised to increase pierce delay but thought it was odd to make it longer than hypertherm indicates. I’ll try some more cuts and see how it goes.
Ran a cut with a longer line and saw the THC active/ok lights coming on. Seems like it is in fact working. Does it not adjust on short curves or will the THC not indicate active or ok on curves?
Is there a set offset fkr the pierce delay? Im trying to get my 45xp dialed in and would rather sort this stuff out via the web than eat up expensive HP consumables…
Has anyone started making a THC settings chart for different gauges/materials/etc? THC always fails about halfway through my cuts, so i’ve had to turn it off. Using default settings with ~0.125" steel. Thanks!
what PH and CH are you using? Also, are you using smart voltage?
Sorry it took so long to respond, had some laptop issues. Attached are pictures of all the settings. Everything should be default, so i’m not sure what is going on?
Hello. What happens if I am getting 2.3-2.7 v across A1 and Gnd (as suggested in troubleshooting step c4 above)? I still get THC fails (Plasma arc lost). I have verified all volts and polarity from the cutter into the div input (2.4-2.8 or so) and then from vim out to the CNC enclosure (2.1-2.4 or so), and have gone through the above dmm testing on the chip. I’m at a loss? My machine cuts fine with out thc enabled, when I enable it it fires for a sec then shuts off with a lost arc error. Without thc enabled it cuts fine as long as the metal is flat.
We are running the B1 test as we are having trouble with cutting. What does it mean if you are getting large fluctuations in the volts while running this test? Range from 46 to 90. Doesn’t do it every time. 2 out of 4 times so far. The other 2 it was 90 to 95.
krmnelson73,
Measuring large voltage fluctuations across the Raw voltage pigtails coming from the plasma cutter can mean several things. In order of likelihood, first, consider the voltage regulator inside the plasma cutter. Is the voltage regulator in the plasma cutter beginning to fail? Is this week’s cutting voltage similar to last week’s? Is the cutting voltage slowing decreasing? Answering yes to these question would suggest the voltage regulator is beginning to fail. Contact the plasma cutter manufacturer and explain to them the symptoms you are seeing.
Less likely than voltage regulator failing would be loose connection of the pigtail leads in the plasma cutter or the voltmeter probes are not firmly in place. To rule out these possibilities ask, “Have the leads been in place for a long time?”. “Did you just recently move the plasma cutter?” Visually inspect the connection (cutter unplugged for safety), wiggle the wires and retest.
Still less likely, is the resistance of the cutting circuit (work clamp connection, metal wavy, metal surface condition) varying during the cut. These are not likely candidates but keep open to the possibility.
Hi Thomas,
We have inspected the pigtails and they have a good connection. They have been connected for about a year now. I spoke to Razorweld yesterday and they asked for videos. They came back with "do not use an extension cord on the cutter (it is the appropriate size for the cutter), it has to has its own circuit (which it does), and water level too high and splashing the torch. We use a machine torch normally but put on the hand torch to make sure it wasn’t the machine torch. We used the hand torch on the OG table for a long time without any issues with the torch. At a loss for how to handle them. We do believe the cutter is failing somewhere. Just not sure how to get it addressed.
I do not know if the voltage has changed from previously. I really haven’t paid a lot of attention to the actual numbers. They fluctuate from cut to cut, day to day. It isn’t consistent in anything it does.
In the line test, it would cut good and volts vary. Then not cut through and volts stay steady. Same sheet of metal, same position of ground clamp, same line test parameters. Just move the start position down 1" and go within a few minutes of the last cut. This is what we were experiencing when cutting work as well. I would run the same program many times and it would cut well. Then, run it a few days or weeks later and have to totally redo the program settings, slow it down, increase pierce, etc. Now, you just put in a new tip and electrode and it won’t cut the same program it just cut. Slowing it down to make it work, defeats the purpose of using a smaller tip and makes the dross impossible to remove.
Beyond frustrated at this point.
Kristi,
Consider playing their game:
Take a picture with the plasma cutter plugged directly into the wall (no extension cord).
State the plasma cutter has its own circuit (and measure input voltage while cutting to prove the cutter is receiving stable voltage at operational current draws).
Reduce the water in the table. You will need to be the judge of how low before the torch damages the tray.
Ask the plasma torch manufacturer how much voltage variation can be expected on a cut. You stated, “In the line test, it would cut good and volts vary.” What was the range of voltages observed?
Make a note today what voltage you are seeing on what material. Consider keeping a log.
If manufacturer of the plasma cutter considers the voltage regulator OK then you will need focus on Torch Height Control. For THC consider measuring various points in the Torch Height Control circuit like this: Measure B1 then B2 then B1. Next C2 and then remeasure B1. C3 and then B1. C4 and then B1. What is the variation in B1? Are the other values within their expected ranges?
We switched plasma cutters. The Razorweld is now the hand sheet cutter. We don’t have the same wall outlet for the plug on the Razorweld and decided it wasn’t worth changing the outlet at this point. We have 2 welders that use the outlet we have in the wall. Plus, it would be about $100 to ship the cutter to them if we got them to agree to even look at it. $100 to ship it back. Who knows if they will be honest and determine there was anything wrong with it. We had a new Primeweld Cut60. Hooked it up and we are cutting again.
Hello, I am new to my CrossFire Pro, I have already done all the tests but nothing shows the voltage on the FireControl.
I have not been able to make my first cut 
can you do a manual fire from the trigger on the torch AND from within fircontrol?
Please follow this troubleshooting flow chart below it should identify your problem and propose a fix for it.
THC TROUBLESHOOTING FLOW CHART REV. B
I actually had that happen to me today. Found it was because I had my torch holder height set incorrectly. I’d been messing around with things 
Hi, I followed the troubleshooting flow chart but nothing solved the problem, i dont know if theres a bad parameter in Fusion 360 or something wrong in FireControl:
