Rods "Spaceship" Scratch built Plasma Cutter build

rodw wrote:

As Tommy (and others) have pointed out, there are other methods to do plasma with Linuxcnc but they have missing features.


A couple now have good success.

The only thing missing is the kerf crossing and anti-dive ( they are the same thing ), and that is something that i for one do not get why it is needed as i have never had the torch dive deep enough to touch the plate till i was cutting 25mm thick plate, and that got solved by simply lowering the THC speed.

Does a couple mean that i have 11 machines working all day every day for several years without a single issue ?
And that is cutting mostly 3mm thick plates that warp over 5cm during cutting, sometimes way more. One of them cuts 10 and 12mm all day long at 100A and the only time it stops is during summer when the plasma transformer overheats and shuts down for cooling 15 minutes and continues cutting again.

Again, i did not do that config, some other users on this forum did, thank you very much whoever did it, i did modifications to it to work with cheaper THC's, so i am not insisting on it because it has something to do with me, i am insisting on it as it works and it works perfectly well for anything but extreme cases.
I am insisting on it as some of you insist on posting all over the place that Linuxcnc can not do THC and is useless for plasma cutting, that simply is not true and is doing to much damage to Linuxcnc.
At least one had the decency to try it and dismiss it as he does not like the Axis Gui.
You should have at least tested it first.
My advice if anyone cares, take that config, or the VLCDTHC that also has voltage control built in, make it work with Mesa THCAD. Given enough time i intend to do that, but i do not know when. Am in the process of making it work with servo drives and the loop closed in Linuxcnc.
Again :
Linuxcnc + Plasma = IT WORKS
Linuxcnc + THC = IT WORKS

As usual, admins if you consider any of this inappropriate, please delete this post.

Don't think I've ever said linuxcnc does not work with THC or plasma, just always seems a long setup process plus a lot of fiddling. (I'm considering it for turning as I've got an old CNC lathe to upgrade)

Linux is always considered to be a highly configurable OS, just the time it can take for you to get it the way you want it plus understand what you need to do can be a long road. (...under the bonnet / hood time...)

Robert, that was not addressed at you, i thanked you in the above post before i replied as i did agree with all of what you said, save for the little bit that Linux is hard, it was hard, now it is much much easier than any windows for normal users.

tommylight wrote: Robert, that was not addressed at you, i thanked you in the above post before i replied as i did agree with all of what you said, save for the little bit that Linux is hard, it was hard, now it is much much easier than any windows for normal users.

Tommy. sorry if I offended you. I hold you in the utmost respect and you have given me a lot of guidance on this journey of mine. I know you have had great success with your proma config and others have too.

This build has become an experiment in the use of the external offsets branch and guided by a desire to build a THC within linuxcnc rather than rely on an external THC controller. I have an external controller here to fall back on but at this stage I'm not done with external offsets yet.

Since I've started this, there are at least 3 others who have built working systems using PID based control within Linuxcnc that are giving good performance. Eventually, I am sure a working solution will emerge and I truly hope it can be locked down into a standard part of linuxcnc. The reason why I want to do this is that it has been said that the best THC's are built into the motion controller (eg. like the Hypertherm controller mentioned a few posts ago). Because Linuxcnc is_the_motion_controller and we have a means to accurately read the torch voltage into linuxcnc, I can't see why this can't be done.

rodw wrote: Tommy. sorry if I offended you. I hold you in the utmost respect and you have given me a lot of guidance on this journey of mine. I know you have had great success with your proma config and others have too.

Because Linuxcnc is_the_motion_controller and we have a means to accurately read the torch voltage into linuxcnc, I can't see why this can't be done.

Rod, you have never offended me. Even if someone did offend me i would not bother to reply.
On the other hand, i get really p/o/ when some individuals insist on what is absolutely not true about Linuxcnc.
Linuxcnc is extremely flexible and can be made to do almost anything as far as CNC goes, so i have no doubt you and others can make it work, and Icelander has a working solution already.
Moving on.

Tommy. I think with the benefit of hindsight a plasma machine is not recommended for a starter CNC project. A simple milling machine should be able to be configured and working in a day using stepconf or pncconf if a new user takes the time to read the introductory docs. And I agree the current Linux distros are a no brainer to install and much nicer than Windows today.

Anyway back on topic! I mucked about replacing the faulty proximity sensor with one laying around that initially tested as working only to find it was faulty once installed (which explains why it was laying around no doubt). So I'm waiting on parts again.

This looks like its the second time this same sensor has failed. I'm wondering if it was becasue it was an NPN sensor and required a pull up resistor to work with my Mesa card. The new one is a PNP one so I should be able to remove the resistor. Maybe it will last longer.....