Spurious engagement of Plasmac's Anti-dive

Agree 1 second might be too long but maybe 10 readings (0.01 sec) is too short....
This is probably as good a plot as any of an Arc establishment and cutting normally without THC (Everlast 50 amp)



And arc establishment, crossing a kerf and running off a sheet


Close up


And now with plasmac close up of the original one we've been discussing no THC (Thermal Dynamics A120)


So you can see the arc voltage peaks quickly during piercing (why we use a THC-on delay ) then stays very stable.

Also its clear that better quality machines have a much cleaner torch voltage but some of that could be due to me adding stuff to counter noise on the Everlast. So you have a much better process control signal if you spend the money.

The rate of change is a much better indicator of kerf crossing because it is several orders of magnitude higher than what can happen from normal warpage (but with the plasmac THC, this should be very little).

We are going to nail this eventually.

I implemented lowpass filtering and modified plasma_run.py to increase the adjustment range of Kerf Crossing Override.

This a short cut with Kerf crossing enabled but not cutting across a kerf.



This is a second cut on the same material now cutting across. That first spike is due to THC enabling while the arc was already in cutting in a kerf.




I just arbitrarily doubled the override threshold to 1000 with these cuts but it looks like the behavior is appropriate.

Looking good! so you are saying this now has a working kerf crossing feature for your machine?

Its interesting that you have been able to filter the signal out quite nicely.

rodw wrote:

Looking good! so you are saying this now has a working kerf crossing feature for your machine?

Its interesting that you have been able to filter the signal out quite nicely.

So far the results look very promising. I want to run different material thickness and feed rates before declaring victory.

phillc54 wrote:

I would really like to see a comparison between your last result and the changes I suggested in this post

Phil, I will definitely test it but you have to bear with me as I don't have an abundance of spare time to test. Your proposed code change is next in my queue.

On a related note, would guys prefer halscope or halsampler?

Halscope is good. Sampler is really only good if you want to analyse in s spreadsheet eg. Linear Regression etc.

It would actually be very good if halsampler had a --csv switch