Valid Arc Lost 2

Thanks Rod !

I was actually in Jaycar to buy a single resistor just before! feels weird tapping a card to buy something for 70 cents.

So just and update.

I wired in that circuit and its sort of a success.

PREVIOUSLY:
- to do a straight test cut in the run tab, the Arc OK light would not light up in the bottom left and the torch would fire for 1 second, stop, give a valid arc error, retract to the max Z height, and pierce again. It would repeat this process until i stopped it.

NOW:
- I fire a test cut and the arc ok signal comes on momentarily, but then the torch turns off, retracts to Z max and stops there, (and I think it automatically triggered the E-stop). It would not keep peircing like previous.

Unsure if this points to a software issue? Perhaps any lowpass filter or debounce settings in the ini or hal files (i have never set anything for these).

I will go to Jaycar tomorrow and buy some resistors and see if this helps.

little_sparky wrote: Thanks Rod !

Unsure if this points to a software issue? Perhaps any lowpass filter or debounce settings in the ini or hal files (i have never set anything for these).

Would you mind posting your config here? If you are on v.171, you can click "backup" in the config page which will dump a compressed file into your home folder, and you can post the file here.

Otherwise your <machine_name>.ini, <machine_name>.hal, and <machine_name>_connections.hal files would work. You may have to toss ".txt" at the end, I cant remember which file types the forum accepts and which it does not.

Just a long shot but I have a similar machine and the torches that come with the machine need at least 90 psi into machine and at least 55 psi flowing out of torch to keep blow back start working. ???

Changed the title since there is another longer topic with the same title and content.

kramerda wrote: Just a long shot but I have a similar machine and the torches that come with the machine need at least 90 psi into machine and at least 55 psi flowing out of torch to keep blow back start working. ???

hmm I would hope this isnt the issue because I just bought a new peerless compressor that pumps out 175 psi and when I disconnect the hose you can definitely tell there is a lot of pressure there. I might double check the plasma cutters own pressure gauge in the morning to see if i need to adjust.

snowgoer540 wrote: Would you mind posting your config here?.

ill grab it first thing in the morning

little_sparky wrote: I might double check the plasma cutters own pressure gauge in the morning to see if i need to adjust.

That has to be done while the air is on, while the torch is blowing air. Some plasma cutters have a switch just for that.
The pressure on smaller units has to be 5 to 5.5 Bar or 75 to 83 PSI, while bigger industrial ones need at least 7 bar or 105PSI. Anything below or above that might case miss fires and extinguished arc's .
Also when buying compressors for plasma, always check the volume per minute they can put out, it should be over 250 Liters a minute for small shops that do occasional work and at least 400 for all day work.
Another thing, noticed on youtube that in US they claim the volume for compressors at a very low PSI value, not at the max the compressor can do, and that is useless, and that trend started also here in Europe as i witnessed yesterday.
Last one i bought new was made in Italy and could do 420 Liters a minute at 11 Bar, so that was enough for two plasma cutters running all day long, but a 420L/m at 8 Bar can not keep two plasmas running all day.

Yeah, I was scratching my head over this a while ago until I realized I needed to turn up my regulator. As mentioned check the pressure during a cut. And check your plasma manual for the correct pressure.

tommylight wrote: Last one i bought new was made in Italy and could do 420 Liters a minute at 11 Bar, so that was enough for two plasma cutters running all day long, but a 420L/m at 8 Bar can not keep two plasmas running all day.

I think the US quotes displacement which is very misleading. Here in AU (and probably also in EU), they must by law quote free air delivery (FAD) in accordance with the Australian standard. This is much lower so 320 litre per minute FAD will do the job for a decent sized plasma table (what I have) but lacks the headroom so will cycle a lot so it will be hotter and have more water in the air so for industry a 420 LPM FAD is a better option which is getting up into 3 phase power.

I'm pretty sure the issue is the low current ArcOK in this case.

I started a new topic about selecting a compressor for plasma cutting under the PlasmaC section of the forum:
forum.linuxcnc.org/plasmac/39991-choosin...r-for-plasma-cutting
Please feel free to add more info.