THC Problem - Linux/THCAD10/SheetCam

Hey All,

Now everything running I'm having a few issues I would like to fix and need some guidance.

1st issue - from time to time, when cutting the Z axis will dive down and trigger the probe sensor. I'm guessing that its trying to get the voltage high and is diving to try and make this happen.

2nd issue - diving on corners. I know this can be adjusted in the settings or post processor. I just don't know how. these are my current settings.

3rd issue - PNP sensors on the limit switches trip out. I know I need some sort of debouncing in the Hal file, I just don't know what this looks like or how to do it. If someone has the lines of code for this can you post it please.


Link to my build with most details.
forum.linuxcnc.org/show-your-stuff/42411...ade-cheap-plasma-cnc

issue 1, you have it the wrong way around
torch will dive to lower the voltage, the voltage gets bigger when the gap gets wider. that is why when the torch slows, the kerf gets wider, the voltage gets higher and with thc the torch dives to LOWER the voltage sensed

issue 3, could be a few things. what plasma cutter are you using (make, model, link?)
how have you wired your proximity sensors?
(sketch the circuit please)

how much load do you have on the sensors, do they feed directly to an input pin. the impedance of the Mesa input pins on 7i76 is about 20k


automation-insights.blog/wp-content/uplo...-768x1000_update.jpg

Thanks Tommylight,

I'll change the heigh per volt now.
corner lock on 99%.

Thanks Robertspark,

I'll try adjusting the set voltage to a higher voltage.

Thanks Guys,

Settings changed, works great.

However tonight I cut some parts from ally, all went well with new settings, then boop, no more torch fire. can't get the board to fire the torch. tried resetting and using the pulse button in the GUI. NOTHING. every now and then the board will light up to say it has turned the torch on, and the relay will light up, but no spark.

Any ideas?

changed nozzle/electrode (first thought)
all tight
60psi

Plasma will start (pilot arc) if I short out the start circuit.

MESA board will light up to say that the torch should be on (sometimes), relay will trigger to tell the plasma to start, plasma will try and fire then stop. then mesa will stop triggering the relay.

Tried changing relays, restarted the system several times, changed wires, etc.

No errors in LinuxCNC.