Post Processor for Mach3 with a proma thc and no floating head

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ernesto
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Post Processor for Mach3 with a proma thc and no floating head

Post by ernesto »

Hi everyone,

I've probably put at least 40 hours into searching this here and on the internet and I've just been spinning my wheels. It's probably one of those too simple to ask questions but I've tried everything I can try and am still at a stand still. I'd write the code by hand but writing it for a THC is just something I don't quite get.

I've been fighting a lightning 5x10 for a few weeks now and finally got everything running smoothly, tuned, square, and returning to zero accurately but can't find a post processor that makes any sense at all. I've tried every single post processor in sheetcam with Mach in the title and they all do strangest stuff. Nothing I've been able to do will produce accurate g-code. As an experiment, I drew a 2" square in librecad, imported it into sheet cam, and ran every post. Most of them had a few lines of code that just repeated g28.1 and only produced a single diagonal line. I've gone through sheetcam setup tutorials and I'm pretty sure that everything's set up correctly.

Which post processor would you guys recommend for this setup?
Les Newell
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Re: Post Processor for Mach3 with a proma thc and no floating head

Post by Les Newell »

The THC posts only control the touch-off which you don't have. They don't do anything with the torch height control itself. The correct post for this setup is the 'Mach3 plasma' post. If you have trouble with that post the problem is probably elsewhere.
ernesto
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Re: Post Processor for Mach3 with a proma thc and no floating head

Post by ernesto »

I appreciate the suggestion but that post was the first one that I tried. It kept stopping randomly and raising the z axis whenever the plasma tried to turn on and the z-axis seemed to run in reverse. Now that I'm a little more caught up on g-code, I could probably make it work. I ended up getting it to work last night by using the Mach3 plasma thc-scriber post and just manually editing the g28.1 sections out of it. I was getting great cuts and the thc was working perfectly. This morning, a friend tack welded a jig while it was sitting on the table without unhooking the plasma work lead and it seems like it's time for a new electronics package. The plasma cutter still works fine manually. Mach and the thc are doing their thing, and all lights on the gecko are fine. The steppers worked but the plasma wouldn't fire even though the light in the diag scree was lighting up. I restarted everything and now can't jog or run a program but the torch on button in mach still fires the torch. I'm so tired of windows, mach3, and old iffy computers that I'm now on a mission to get thc working with a raspberry pi/grbl shield.

Thanks again for the help. I think we can call this issue solved.
Les Newell
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Re: Post Processor for Mach3 with a proma thc and no floating head

Post by Les Newell »

It sounds like your initial problem was a THC configuration issue. OK, for testing first completely disable the THC. Get it working that way before trying to get THC working.
ernesto
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Re: Post Processor for Mach3 with a proma thc and no floating head

Post by ernesto »

The THC configuration is really easy, and was never changed after working successfully a few times after initial setup. Since I can get it running perfectly, change nothing, and it all randomly scrambles up again, combined with other strange behaviors unrelated to cnc, I'm pretty convinced that the computer is toast. Now I'm in the situation of choosing whether to buy another old, likely unreliable, computer with an unreliable and unsupported operating system or ditching it all and running the thing with this: https://www.zyltech.com/store/p186/Rasp ... tible.html

This guy seems to have a similar setup working. https://www.youtube.com/watch?v=7vbhoMMm8bg
Les Newell
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Re: Post Processor for Mach3 with a proma thc and no floating head

Post by Les Newell »

I'm pretty sure GRBL can't handle THC. The machine in that video doesn't look like it has THC.
ernesto
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Re: Post Processor for Mach3 with a proma thc and no floating head

Post by ernesto »

It's taken some research but I think I figured it out.

I'll be using a Proma THC-SD to control the z axis once the torch fires. When the torch is turned off, grbl will be put back in control. It looks like GRBL supports G28.1 too so it should be able to support gcode to run a floating head too. When I get it all running, I'll make a new thread and link it here.
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