Cut blowing out at random. (youtube video link)

[Deezl Smoke]

So, I have plenty air volume and pressure. Filters and refrigerated air dryer.
Hypertherm PM105 head, 480 three phase, 25' torch.
Arclight Arc max table. I use Sheetcam CAM, and the table came with Linux CandCNC using Arclights post processor.

When the table was new, 2019, even without the air dryer and better filters, I could cut 1.25 mild with exceptional results. Things have been continuously degrading to the point that now I can't even cut .75 mild using new Hypertherm consumables. Yes, actual Hypertherm from a local Hypertherm dealer, no amazon or 10th party acme behind the hardware store dealer, but actual new newest 105 amp swirl ring, nozzles and electrodes. O-rings good and freshly lubed. Air pressure gauge at back of power head stays at 120psi while table is running. Ground clamp attached to fresh bare metal with no loops in the cable. No heat build up at ground even after several minutes of 105 cutting.

Things I've tried. Slowing the cut speed. Raising the preset air pressure up to 4psi. Speeding up the cut speed. Speeding up the DTHC sensitivity.

In the picture of the desktop, you can see the thc is on and the Z shows the proper .1250" height, but it does not vary as the torch moves, then all of a sudden it starts working and will follow the plate, then quits working and the torch dives into the plate, or drags along for a bit, then jumps up again. No faults or codes or messages anywhere that I can find. But the torch height is not what's causing the issue in the video and the 2 other pictures here. This will happen even with the thc off and the torch at the right height above the plate. Usually about 20 minutes into cutting. Even after this blow out, the nozzle and electrode are in great shape. This will happen even 1 minute after a new electrode and nozzle. So that variable doesn't seem to affect it either.

Thanks for looking and any help you can offer.

dthc 2024.jpg

blow out 1.jpg

blow out 2.jpg

[acourtjester]

Did you change steel suppliers, maybe the quality or the steel has changed. Or if it happens in a section of the table, you have a kink in the torch air supply.

[Deezl Smoke]

Did you change steel suppliers, maybe the quality or the steel has changed. Or if it happens in a section of the table, you have a kink in the torch air supply.

This is customer supplied steel. And yes, this has been a topic of discussion with him. The thickness is within stated variance. But I have noticed the quality of all steel available in my area has degraded since the 2020 experiment.
Just went back up and gave it another try. Didn't even make it one part this time. Lots of issues with the controller program. All lights and warning of the hardware are good, but the program must be corrupt, IMO of course.
So here's some more of why I think the program is corrupt. This screen shows the torch is still at .1250" but it had just crashed into the plate and I hit stop.

20240428_130226_resized.jpg

At that same time, here's another youtube upload of homing the Z from that .1250". It's been doing this a lot more lately. After each part, even if the cut was successful, I'd home Z and would get a negative number.

[weldguy]

I have seen that cutting issue with poor quality steel also. As for your z axis problems it is very strange that with THC off the z axis still moves. Not sure what to say about that. It could be a long shot but I would try shutting everything down, unplugging everything from 110v for a minute, plugging it all back in and giving everything a fresh reboot and restart. I don't think these 2 issues are connected in any way do you?

[Deezl Smoke]

I agree. These two issues are separate, but may be from the same source, the P2 program. At least that's what I'm leaning towards at this point.
I have done the shut down and unplug then reboot a few times. Often it does help with minor issues. But this seems to be more of a corrupt program or broken......firmware? I've replaced everything but the mini computer when the lightning strike hit a few months back. But the cut issues was there before that.

[Deezl Smoke]

Ok so, a quick update so to speak. After the afternoon on the phone with Arclight, (awesome crew) we performed a lot of tests. The only real head scratcher is even the voltage test button on the pwm shows about 11 volts higher than preset.
So to eliminate yet one more variable, I replaced both cat5 cables while waiting for Arclight to open tomorrow. The torch voltage is staying high, but i videoed an entire cut and uploaded it if anyone is interested.
What is happening now is the Z stays at the .1250" through all cutting. Even though the video shows the dthc is on and all of the proper lights are on and the right color, the Z does not move at all during the cut. Dunno, but the machine is working fine now. Making good cuts, not blow outs in the entire plate tonight.

[acourtjester]

Good to see you are cutting and finishing the operations. My question is why does the arc voltage not change when passing over the slates when cutting, and the DTHC not change slightly? Could your problem be in the DTHC and it has now died so no voltage changes recorded?

[Deezl Smoke]

Good to see you are cutting and finishing the operations. My question is why does the arc voltage not change when passing over the slates when cutting, and the DTHC not change slightly? Could your problem be in the DTHC and it has now died so no voltage changes recorded?

Exactly !! DTHC must've crashed like 95% anyway. This morning, things were cutting right along just as you see in the video, then on the forth part, the DTHC suddenly started working and the cut blew out as well as the torch crashing into the plate. So now I just run with the thc OFF.
There should always be a small bit of Z movement when thc is on and that in turn, as I understand it (ya.....right Don, you understand....) should correct the voltage. ? I think. No faults, no messages, nothing, not even a light out of color. The DTHC module is new after the lightning strike.
There may be a chance that something else, some very small and easy to overlook item was compromised in the strike and is intermittent in it's operation. Really frustrating.

[TJS]

Not sure where you stated where you are turning your DTHC off(Command CNC or Sheetcam). I don't use the DTHC anything 3/16" and thicker. I don't feel there is a need to as it will not really warp. I turn my DTHC off in sheetcam. There is a Disable DTHC checkbox for that operation. Caveat: I have used it a couple of times where the torch comes back over the Lava flow (initial pierce volcano) and it has moved over it. That is for that particular part I was cutting. Otherwise I just let it ride without the DTHC.

[Deezl Smoke]

Not sure where you stated where you are turning your DTHC off(Command CNC or Sheetcam). I don't use the DTHC anything 3/16" and thicker. I don't feel there is a need to as it will not really warp. I turn my DTHC off in sheetcam. There is a Disable DTHC checkbox for that operation. Caveat: I have used it a couple of times where the torch comes back over the Lava flow (initial pierce volcano) and it has moved over it. That is for that particular part I was cutting. Otherwise I just let it ride without the DTHC.

I have been turning it off at the Command controller. Is there a way to be able to bump the Z during cutting if I turn it off in sheetcam?

[TJS]

Why would you want to turn it on anyway for thick material. I do not see a benefit as there is no warpage. Possibly I am missing something. And NO I do not think you can turn it back on if you disable it in sheetcam. Have not tried it though.

Also I had issues with my torch hopping up and down on thicker stuff. I slowed my accel down, all axis (in the configurator) and made a new profile called "Thick Material". Make sure the DTHC response is slow (If I used it but I don't for thick).
So now I have two ICONs on the desktop. One called "Plasma" and the other "Thick Material".
Do you have any cut rules that you use for this. I have never added any and I just keep the canned EOC cut rule. Command CNC states do not stack cut rules.

[Deezl Smoke]

Why would you want to turn it on anyway for thick material. I do not see a benefit as there is no warpage. Possibly I am missing something. And NO I do not think you can turn it back on if you disable it in sheetcam. Have not tried it though.

Also I had issues with my torch hopping up and down on thicker stuff. I slowed my accel down, all axis (in the configurator) and made a new profile called "Thick Material". Make sure the DTHC response is slow (If I used it but I don't for thick).
So now I have two ICONs on the desktop. One called "Plasma" and the other "Thick Material".
Do you have any cut rules that you use for this. I have never added any and I just keep the canned EOC cut rule. Command CNC states do not stack cut rules.

If I turn it off in sheetcam, there would be no way to turn it on as no code for it would be included. IMO.

When cutting a lot in high amp, the build up on the slats makes even the thick plate off level enough that there may be as much as 1/2 to 3/4" height difference X and Y, and large parts don't do well with that much differential. Yes, I do need ideas on how to fix the slat issue. But that will be after this job gets finished. I still have 100 parts to get cut out of 3/4.

I too had that "sewing machine" issue a while back. I'll have to go through the old threads and see what solved it.

Here's a screenshot of the path rule set. Les at sheetcam helped me with the issue I had with the arc radius. All good now.

sheetcam screen.jpg

After doing the air quality test, my air supply is clean of dirt and I was told dry enough, but as soon as my air compressor supply store opens, I'm going to buy a new higher quality regulator and moisture control. While preforming that air test, I could audibly hear a fluctuation in the air. After about 5 minutes, said fluctuation disappeared. I can't help but wonder if the solenoid in the Hypertherm is compromised as well. So I may order one just to eliminate that variable.

[weldguy]

1/2" - 3/4" variance on your deck is pretty significant. May be worth taking some time to address that before moving ahead with a big 100 piece job. Knock a bunch of slag off with a hammer and then get the grinder out to flatten things out.

I have heard variances in air noise from the torch due to moisture issues in the past, I would be interested to see what one of your used up nozzles and electrodes look like.

[Deezl Smoke]

I thought I had a picture of the nozzle and electrode, but I do not. I'll get some later and post.
I did just go get a new Parker regulator from the local compressor supplier. Hopefully it will help as the one on there now is an amazon item. Been working ok, but.....

[djreiswig]

1/2" - 3/4" variance on your deck is pretty significant. May be worth taking some time to address that before moving ahead with a big 100 piece job. Knock a bunch of slag off with a hammer and then get the grinder out to flatten things out.

I would think that much difference would cause some significant beveling on thick cuts.

[Deezl Smoke]

I think it is the variance in plate level. As I was watching the torch amps go up as the X moved right, then stay high On Y movement, then go down as X moved left. It would have the greatest tendency to blow out when the torch volts got to near 180. Preset is 151. The only time the volts would get near 150 was when the torch was dragging on the plate.
So, I will need to order some DTHC parts asap. But to get by, as this job needs completed by friday, I just ran the torch around the table and found the low spot, then shimmed it to as close as I can.
I'm pretty sure my new Parker regulator had no real affect, but the piece of mind knowing I have a good one now instead of the amazon item is good.

[Deezl Smoke]

Oh ya, and another observation was, the heavy build up areas on the slats also seemed to contribute to the blow outs. Acted like thicker plate in those areas, and the dross that was stuck to the slats, then became stuck to the plate. Real mess trying to pry the plate up off the slats.
Bevel.

20240429_170557.jpg

[weldguy]

When the torch is cutting and passes over a deck slat it is just like cutting thinker material and can cause some minor issues. If the slats are new and thin, not such a big deal but yours look like they could be 1/2" wide now with all the slag build up. Again I believe it will be well worth your time to clean the slats you have or replace them. Get them thinned out and get them level.

[Deezl Smoke]

When the torch is cutting and passes over a deck slat it is just like cutting thinker material and can cause some minor issues. If the slats are new and thin, not such a big deal but yours look like they could be 1/2" wide now with all the slag build up. Again I believe it will be well worth your time to clean the slats you have or replace them. Get them thinned out and get them level.

I removed 2 slats, then flipped the third, then remove 2 etc. Needed to be gentle setting the plate on the table at that point. No difference.
I finished the job today. Customer is very patient and understanding. I'll discount the job to whatever he sees fit.
To finish, I had to slow the torch speed to 20ipm from Hypertherm's 33ipm. I had to reduce the cut height to .085" instead of Hypertherm's .125" and run without thc. This still had an occasional issue, but the cut was very good with virtually no flare.
Went through very expensive nozzles, electrodes and a few shields.

So now I have Arclight quoting me a new console and a new 105PM. They said they can test my current system for a small fee and quote me the repairs. I'm hoping I can afford it after this expensive debacle, then I will have a backup system for next time. And yes, there will be a next time. That's just how my life has gone for it's entirety.

In the mean time, I'll drain the table, clean it, replace the slats, and maintain the rails, gears, and belts etc. Going to re-level it while empty and check it again full of quench guard.

[weldguy]

That's great that you pushed through it and got it done. Hopefully the customer is happy and pays well. Best of luck with your maintenance and mods for the next big job