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

Why don't you try a timedelay of say 0.2 to 0.5 seconds after torch on and use that as a ArcOK? Leave it on until the cut is finished.

It seems like your machine is not a candidate for synthesised ArcOK.

rodw wrote: Why don't you try a timedelay of say 0.2 to 0.5 seconds after torch on and use that as a ArcOK? Leave it on until the cut is finished.

It seems like your machine is not a candidate for synthesised ArcOK.

Would you mind expanding how to achieve that, ie where would the time delay be put and how do I change it as ArkOK.

Before your post . I have been testing again and notice that the ArkOK stops on until the volts drop to zero which take a few seconds to do that. I can fire the torch using a push button across the relay contacts when the air is still purging

Edit: Is there anyway I could trick the THC into zero volts at the start. ?

You would need to have Arc OK Low set to higher than this stray voltage you have.
If a pushbutton can fire the torch then the torch on signal also should.

It would probably be worthwhile running Halscope on these pins plasmac:torch-on plasmac:arc-ok-out plasmac:arc-voltage-out

On another tack it may be worth trying the lowpass filter as explained here:
linuxcnc.org/docs/devel/html/plasma/plas...r-guide.html#lowpass

Again you would need to have Arc OK Low higher than the stray voltage.

phillc54 wrote: It would probably be worthwhile running Halscope on these pins plasmac:torch-on plasmac:arc-ok-out plasmac:arc-voltage-out

On another tack it may be worth trying the lowpass filter as explained here:
linuxcnc.org/docs/devel/html/plasma/plas...r-guide.html#lowpass

Again you would need to have Arc OK Low higher than the stray voltage.

Thanks for your time Phil. I am sorry to be a pain.

I have tried ArkOK at various volts up to 100.

The relay that fires the torch just briefly triggers but does not hold on.

I have tried the lowpass filter was at zero have tried 50,100,200 and with ArcOK_Low at 100.
it doe not change the hovering volts 0-20 after the cut

What is your Arc OK High set at?