Showstopper Plasma Cutter retrofit

OK, so the machine is usable, right?
Personally i never use ohmic sensing and i have removed quite a few of existing ones from old industrial machines as they were very flaky and more trouble than worth, but Rod has made some good work on making it very usable, so i might just give it a try ... when i get a torch with a shield.
Sorry i can not help more with it.

SteveatSteelCut wrote:

It's a lot faster than the float switch, ...

Yes it is and that is unfortunate as the probing is done twice every time at very low speeds.
I am beating a dead horse, as i have insisted from the very start of PlasmaC that should not be implemented at all, only a single probe.
On a plate with over 200 pierces, probing time is in hours, no matter how fast the Z axis is.

tommylight wrote:

Yes it is and that is unfortunate as the probing is done twice every time at very low speeds.
I am beating a dead horse, as i have insisted from the very start of PlasmaC that should not be implemented at all, only a single probe.
On a plate with over 200 pierces, probing time is in hours, no matter how fast the Z axis is.

It is probably an incorrect setting, my table only probes once.

SteveatSteelCut wrote:

Yes it is usable.
When it let's me use ohmic probing it is working great.
It's a lot faster than the float switch, doesn't put pressure on any adjustments, and it doesn't push the material down. It seems like a much more accurate measure for pierce height.

Deleting the var file was a placebo. When you receive that error, it's because the ohmic probe tripped prior to reaching probe height. Generally speaking, this is due to either the torch being wet, a piece of slag completing the circuit, or in the case of my Powermax 65XP, when I used the THCAD Ohmic sensing the voltage used to accumulate for no apparent reason (though I was told this is impossible (by those without a Hypertherm)). After months of testing, I did away with THCAD ohmic sensing in favor of a few diodes, relays, and a resistor or two which sounds complicated but is much cheaper and easier to implement and has required 0 dickering, I can find a post with the diagram if you're interested. You can decrease the sensitivity of the THCAD ohmic by adding resistor(s), but ultimately I still had the issue of the accumulating voltage. You can plot this and see if it might be your issue using HALSCOPE. After a few cuts my voltage would hover near the trip voltage even when the torch wasn't wet.

tommylight wrote:

Yes it is and that is unfortunate as the probing is done twice every time at very low speeds.
I am beating a dead horse, as i have insisted from the very start of PlasmaC that should not be implemented at all, only a single probe.
On a plate with over 200 pierces, probing time is in hours, no matter how fast the Z axis is.

I've seen you say this numerous times on the forum. This has to be a setting/config issue on your part. In an effort to hopefully put the "they didnt listen to me" part of this to bed, I made a video this evening while I was cleaning up the garage. It shows QtPlasmaC (using the PlasmaC component) doing 2,400 probes. Not a single one of them double probed, and it should be noted that all 2,400 probes were completed in ~1 hour.



It should also be noted that I made Cut Height and Pierce Height equal so it didn't look like there was an extra probing move.

I should also note that when the heights/settings are wrong, probing does take longer.

phillc54 wrote:

It is probably an incorrect setting, my table only probes once.

X2, I agree.

rodw wrote:

snowgoer540 wrote:

Deleting the var file was a placebo. When you receive that error, it's because the ohmic probe tripped prior to reaching probe height. 

This cannot happen. Ohmic sensing monitors motion.motion-type and can only activate when linuxcnc is actually probing, If its triggering, it has to be the breakaway or float switch.

That seems a bit odd as default plasmac configs don't use the LinuxNC internal probing, they usually use external offsets.