Another plasma component...

Rod

It is a hack I made to plasmac_run.hal. I added an OR2 between the GUI output pin,plasmac_run.thc-enable and the plasmac component pin, plasmac.thc-enable. The signal from the Gcode file is a M62-M65 P.01 controlling motion.digital-out-01 and is connected to the other input of the OR2. I described the function to Phill a while back in this thread. I think this in the example PP I posted as well.

I will fix my configuration to match the Plasmac branch when the external THC enable function is added back in.

John

islander261 wrote:

Rod

It is a hack I made to plasmac_run.hal. I added an OR2 between the GUI output pin,plasmac_run.thc-enable and the plasmac component pin, plasmac.thc-enable. The signal from the Gcode file is a M62-M65 P.01 controlling motion.digital-out-01 and is connected to the other input of the OR2. I described the function to Phill a while back in this thread. I think this in the example PP I posted as well.

I will fix my configuration to match the Plasmac branch when the external THC enable function is added back in.

John

John thanks. I really think plasmac should have an external hold pin that is by default connected to one of the motion.digital-output-nn pins so the THC can be placed on hold from gcode. In fact, 2 pins or'ed internally would be better as this would leave one for user extensions. (if only to let me continue experimenting with my kerf crossing component before its eventually folded into plasmac).

By my reading of the docs, it would be enough for the or'ed output of these pins to be simply hooked internally to axis.z.eoffset-enable as last time I looked, plasmac sets this to true and never looks at it again.

Docs: linuxcnc.org/docs/devel/html/motion/exte...-offsets.html#_notes

John, which motion. digital-output-nn pin do you use for gcode hold?

Rod

I am using motion.digital-out-01 for THC enable. I never have the THC hold between cuts so switching the plasmac.thc-enable pin before and after the cut works fine for me. I am not trying to cause a "hold" in the external offsets sense, actually I want to reset all the EO counts when I do this. Previously I tried to use the EO "hold" and ran into a bunch of problems with accumulated corrections causing soft limits problems. Just enabling and disabling EO enable fixed this problem. I am just wanting to control the THC Enable check box from Gcode.

John

phillc54 wrote:

THC enable/disable can be done via the new tool table.

Cheers, Phill

Phill, thats not going to allow control from gcode in real time. I must say I'm a bit like John, I just leave it on. One area it can be used is in the sheetcam cutting rules. Probably the most needed area I've seen is to disable the THC before the end of an inside cut before the end of the cut. This can be done with a sheetcam cutting rile. I don't think plasmac is quite there yet with kerf crossing to prevent the dive on the end of a cut when the slug falls away. This dive can be violent on thicker material.

Could you hook motion.digital-out-01 so it can be turned on and off from gcode? It would be better if it was a seperate pin so it could be inverted before or'ing with the thc enable signal so it becomes a disable signal. eg if true don't THC. That way it will have no affect to any existing gcode.

How are you guys adjusting your arc voltage scale. With my THCAD10 wired up and no voltage to the input I’m getting a jumping voltage between 3620v-3650v.

That looks like you have not scaled the voltage at all . More like the frequency at 0 volts with a 1/32 divide set on the board. I use a seperate component I wrote with scaling of 1. YOu can get it from a post in the plasma section here somewhere.

Yeah I have not scaled anything. Do not know how to do it.

Phill

I don't care if we have a pin for external THC enable or I have to put in an OR2 to do it. If I can do it from a tool or materials table that is fine to. I can tell you from the school of hard knocks that what ever is done from external control you want to be enabling and disabling, the EOs the "hold" was a nightmare. My OR2 to control the plasmac.thc-enable pin works really well with no "funny"stuff as a side effect.

I cut three sheets today and the Plasmac branch worked perfectly! I wish I could say the same for the SheetCam generated Gcode. It is sooooo nice to have the torch stop and raise out of the way when hitting a tip up. The reverse run to back up a cut segment so there is no tab left is great! The torch pulse is great for getting the post flow going to blow all of the water and debris out of the way for probing. Having the IHS skip working well is saving a bunch of probing time and consumable wear.

John