Plasma arc dies out during cuts

This week I was working on some 14g material trying to cut out a simple object when the arc would die out during one particular pass. I tried retrying the cut multiple times before moving to a new area and restarted the entire cut.

I had the same thing happen during the version 2 (no picture) but I was able to restart the cut at the line specific line which were broken into multiple smaller instead of one long cut

I am only spit balling here since you have not given much detail such as previous success, cutter, settings, consumables verified to be in good condition, air is good supply and quality and whether you can cut just a simple line generated by FireControl.

I have had that happen when the air did not keep up with the cut, debris in the torch and it looks as if the THC may have been rising toward the end of that far cut as it looked really clean and then you began to get top dross and the cut was not completing.

This can also happen when there is electrical interference with the cable from the computer to the electrical enclosure or some EMI from the work lead or torch cable.

The other possibility is that the contact with the work lead and your work piece was not maintaining good contact.

Or the THC is malfunctioning.

Give more information, check consumables (send pics) and perhaps try the straight cut generated from FireControl.

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Post your .f3d that you used to cut it. Let’s rule out design

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Sorry for the lack of information.

Air supply is good (See image of air compressor and motor guard filter), consumables are pretty dang good (only cutting fluid slashed up on them which I cleaned with acetone). I the dross was caused by me attempting the same cut about three times. You can see where the torch slowly lost the arc as it moved.

With all variable the same I moved the torch up a bit, rezero’d and the same job was successful without issue.

After a couple days pass I updated the job to increase the number of straight cuts to aid in bending it failed to cut the 4th 2 inch line and succeeded on the 5th and failed on the 6th. I reran the job from the line where it initially failed and it was successful for the rest of the job.



UnderRadiatorCoilMount_v2 v2.f3d (128.2 KB)

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I notice that you have your lines being cut with a left sideways compensation vs Center. Judging by the other settings, it looks like it should have cut but just not on the line.

You might try checking your torch height to be sure you are in the ball park. Here is a file from @Phillipw that you allow you to run the gcode and without turning on the torch, stops at the torch height of 0.060 inches.
cut height test.tap (224 Bytes)

You might also try to increase your pierce delay. I don’t know what you had as your pierce delay or cut height.

Really sounds like you ran out of air supply, and it just couldn’t keep up. Maybe others will have other ideas.

Toolpath is going one direction on top and bottom you might want them going in other direction. @ChelanJim is right on using center line for your bend lines also.

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The line cut issues were me not remembering to cut center. (Still learning Fusion360)

Peirce time is .4s for 14g mild steel.

I did observe the torch head lifting during that specific cut. Not sure how to capture that happening. Does anyone know if Firecontrol does some sort of logging that we could use to troubleshoot?

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I wouldn’t think the air compressor in the picture would run have a hard time to keep up. Other jobs haven’t had an issue with keeping up.

Regarding the tool path. I set the entry points to the right side on the bottom lines but it did not create the toolpath accordingly.

I did mess up with the centerline portion. Still a newbie.

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So it was “hunting” for the right voltage with the THC. I am still pretty new at this stuff but you might try increasing the sampling of the voltage in the settings on FireControl. If it was hunting for maintaining a certain voltage and could not find it, it may have extinguished the torch. By increasing the sampling, you might get a more realistic voltage and also give the cutter time to throw an error that could be revealing to the issue.

That sounds pretty low. I have a Hypertherm so we are told to start at 0.5. My setting is closer to 0.7 otherwise I have trouble (doesn’t mean you would have trouble - just something to try).

If you picked the “Center” compensation, you would have been able to get all the lines picked easily and the “manufacturing” would have done a nicer job with the toolpath. No biggie.

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It certainly does look like your torch started to climb before it extinguished the arc.

I can see that you bypassed your air cooler on your compressor and you’re running a motor guard filter, what are you doing to mitigate moisture? What condition is your motor guard filter in?

Could you take a very clear picture of the nozzle and electrode that failed during the cut?

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