Another plasma component...

If during a cut an error causes a pause or the operator causes a pause then the reverse-run signal causes x/y motion to reverse along the current cut path. The maximum reverse position is as far as the start of this cut. At the moment this motion is at the current cut speed (plus/minus the current feed override setting). When a satisfactory x/y position is reached then remove the reverse-run signal then resume the cut via the pause/resume button or keyboard shortcut and a new cut sequence will begin from the current position.

I am in the process of rehashing this so instead of a reverse-run signal the input will be an manual-feed value (from -1 to 1) so that reverse and forward motion will be possible at variable speed while paused.

Cheers, Phill.

Another upload...

Fix timing kludge for dry run.

Rework reverse run for both reverse and forward motion while paused, this is now called paused motion.

Cheers, Phill.

Had a session with it yesterday, using 5i25 stepgens, but could not make it work properly. Need more time.
So far joging works, Y axis does not home, and Z axis does not respond properly to M3 etc.
To be continued......
To do:
Connect the THCAD to have the voltage feedback,
Make all this work with 5i25/7i77 (should be easy afterwards)
Add provisions for changing the cutting current of the plasma cutter ( using relays on older ones or RS485 on new ones, or spindle output for ones that regulate current with a potentiometer ). All this should be automated from the already existing menu PhilC made.
Regards and thank you all,
Tom

No eBay APP ID and/or Cert ID defined in Kunena configurationTommy, sounds cool. Just some ideas for you. grijalvap has shared some RS485 control code here on the forum somewhere.
If you are going to control amperage with a potentiometer, look at an ACS758 Current sensor. Then a LM358 weak signal amplifier to push it up to around 22 volts off a 24 volt power supply. Then you can read that using one of the Mesa analog inputs. Voila current display on your control system!

The ACS758 comes in various ranges, 50 amp, 100 amp, 200 amp and there are some modules on eBay if you don't want to build your own circuit.



www.ebay.com.au/p/Lm358-Weak-Signal-Coll...p2047675.m4096.l9055

I think that we should include this component with LinuxCNC, though maybe we need to wait until reverse-run is merged.

However, it is such a "busy" component that I am wondering if this indicates that we need a new "task" component for LinuxCNC.
Currently everything uses "milltask"
linuxcnc.org/docs/html/man/man1/milltask.1.html
github.com/LinuxCNC/linuxcnc/tree/master/src/emc/task

Which sounds like it does "mill things".

However, the man page seems to say that this is entirely a user-space process, so it might not be what one would change to make a dedicated plasma controller, and maybe the HAL component (definitively realtime) is the way to do this.

Andy, if you dig through the git in the first post (specifically the axis/plasmac sim) it is clearly a real time component.

from plasmac.hal
It would be good to get this into the core code and even better if you could help Phill set up a branch in the LinuxCNC git and also his reverse run work so it is in a position to be incorporated.