PlasmaC torch starting problem (Solved with help from the famous three)

phillc54 wrote:

Clive wrote:

But I was using pierce only and it was that, that was getting rid of the G4

Yes, it only looks for spindle on signals and does it own thing.

That also explains the G1 X 0.000001 you referred to before, LinuxCNC needs to have some motion otherwise it won't turn the torch on.

If you had saved the Pierce Only file then added the G4 codes in then loaded it and run it in Pierce and Cut mode it should work.

Yes I now understand what was happening. What this has now shown me is that the G4P15 after the first cut works but it is not good with a 15 sec delay before each cut . This looks like a problem with the cutter not fire-ing until the air stops.

I have tried it with THC off to no avail. So my next move is to have a temporary button to see if the torch will fire manually as the air is still purging (when it is purging the volts are hovering around 0-18 then when the air stops it is rock steady on zero)

phillc54 wrote:

Have you tried a long Arc Fail timeout?

What would you call long , 15 secs ?

phillc54 wrote:

Yeah, I guess whatever you are using for the G4 time.

Thanks Ok I will try that in the morning. (We are self isolating here)

phillc54 wrote:

Yeah, I guess whatever you are using for the G4 time.

Phil I have now confirmed it is not a fault of the machine as it will fire when I manually used a button to cut the relay out ie shorted the relay contacts.

I think the problem is that the relay is not stopping energised long enough for the torch to fire.

Is there a parameter for that or is there a way to do it in the code I would like to try 2 secs

It could be that the hovering volts 0-20 is messing it up. I have tried OK Low Volts between 5-30

phillc54 wrote:

Clive wrote:

Phil I have now confirmed it is not a fault of the machine as it will fire when I manually used a button to cut the relay out ie shorted the relay contacts.
I think the problem is that the relay is not stopping energised long enough for the torch to fire.
Is there a parameter for that or is there a way to do it in the code I would like to try 2 secs

The Torch On signal should be on the whole duration of the Arc Fail Timeout.

It could be that the hovering volts 0-20 is messing it up. I have tried OK Low Volts between 5-30

It could affect it if the voltage went above the OK Low Volts and then went back below it, that would be seen as an arc failure.

I am not sure how to trouble shoot this. I have not tried OK_low_volts at zero !!

I have noticed when using the temporary push button I see the physical pilot ark come on then it changes to the full arc so there is a slight delay there.

Any suggestions? It will always work on the fist cut. But on the next cut I do see the relay energise very briefly.