THC Issue with Sheetcam and/or Mach3

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AdrianH
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Re: THC Issue with Sheetcam and/or Mach3

Post by AdrianH »

John I will be out at work today so can not spend the time this morning getting the information together, the screen you use is not the same as mine as I use a more standard display, what I would need to do is download the screen and then use the Machscreen.exe program to see how it has been configured and check that against the programming references to see the button definitions.

The delays such as pierce delays it could be adding its own delays into settings on spindle start up, to my working mind should not be used when you use sheetcam to program pierce delays as the two would work against each other.

Anyway give me a day or so to try and get some detailed response back to you.

If still possible you could always try and contact the screen designer, he should be able to answer all your questions on the buttons, but as Mach3 is so configurable for individuals and there machines it may be, like on mine there are buttons I will never use.

But probably later in the evening for me I will be able to respond further.

Adrian
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Re: THC Issue with Sheetcam and/or Mach3

Post by Rodw »

I thought I'd share a voltage plot of an Everlast 50 amp plasma cutter (the green line) at 85 volts captured from within LinuxCNC when cutting 2mm mild steel. Each fine dot in the vertical grid is 5 volts. I'm not sure how applicable this is to your machine.
THC cut 1 - 85 volts.png
For what its worth, I have not seen any appreciable difference in this graph when cutting 8mm steel.

The blue line is the error between 85 volts and the actual volts. Where it starts to vary is when the THC is enabled using Jim Colt's preferred method where the Z axi is controlled internally by the LinuxCNC software (eg. not an external THC).

From the testing I've done, I would question your cut chart settings. I found the best height was 1.7mm and about 1900mm/min so the lower cut voltage and faster speed could explain the lower voltages you are seeing. Data provided by Rtech in the UK pretty well agreed with my testing. They did mention the larger torch (which I think you and I both have) cut at about 10 volts below the smaller one on the 50 amp cutter.

As somebody told me calibrating cut height and cut speeds requires an investment in time, materials and money. Buying a Hypertherm probably reduces these costs significantly as they've already done it.

Some of the tests I've done indicate that I should be able to determine ideal cut height with a single cut about 6" long while LinuxCNC plots volts and height at 1000 readings per second but I've got an electrical fault to fix before I can progress further with the tests I have in mind.
AdrianH
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Re: THC Issue with Sheetcam and/or Mach3

Post by AdrianH »

John I am struggling to open the plasma screen you are using, the resolution size is more than my laptop can handle so I only see the top 2/3'rds of the screen in editing mode, so I can not get at the pink area.

But I have seen your post on the Mach forum and I recognise now why none of the THC stuff you are trying does anything.

You are on demo mode as you do not have a licence and no THC functions will work without a licence.

But a section out of the manual

CV Control: Plasma Mode, if checked, controls Mach3's implementation of constant velocity moves
to suit the characteristics of plasma cutters. It does anti-dive and tries not to round corners in some cir-
cumstances. For the most part, ArtSoft USA suggests you not select this option unless your machine
has very poor acceleration and poor step resolution.

The one part that matters to you and why you can not see any differences

• Only licensed versions can enable THC mode.

There are sections on Pierce delay etc all in the install documents and the link is here if you have not downloaded it yet:
http://www.machsupport.com/help-learnin ... t-manuals/

You want the product and installation manual
Direct link here:
http://www.machsupport.com/wp-content/u ... l_1.84.pdf

But there are other good reads in there for Mach3 or the later supported Mach4

So unless I get better a higher res screen/Graphics card I can not get in the screen set to see what dro's tags etc has programmed into them, sorry.

Hope you get an answer from the guy on Mach.

Adrian
jawneelogik
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Re: THC Issue with Sheetcam and/or Mach3

Post by jawneelogik »

Rodw wrote:... Where it starts to vary is when the THC is enabled using Jim Colt's preferred method where the Z axi is controlled internally by the LinuxCNC software (eg. not an external THC).
Rodw, the more I read about LinuxCNC, the more I want to try it out. I believe it will be a better long term solution for my needs. Thanks for the input.

BTW, my discussions with Hypertherm are done. Next Tuesday I begin setting up my new Powermax85. The problem I faced was created by me when I failed to understand the requirements I had to meet in order to cut my customer's plate. I thought that, based on Everlast's advertised specs, the 60S should have done it, and I made promises based on an assumption. You know what they say about assuming ...
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Re: THC Issue with Sheetcam and/or Mach3

Post by jawneelogik »

AdrianH wrote:John I am struggling to open the plasma screen you are using, the resolution size is more than my laptop can handle so I only see the top 2/3'rds of the screen in editing mode, so I can not get at the pink area.
What is odd for me is that the standard Mach screens are missing a bunch of the parameters we have been discussing and that is why I went to this other screen set. BTW, I have mad attempts to contact the author, but thus far have received no response.
AdrianH wrote:But I have seen your post on the Mach forum and I recognise now why none of the THC stuff you are trying does anything.

You are on demo mode as you do not have a licence and no THC functions will work without a licence.

But a section out of the manual

CV Control: Plasma Mode, if checked, controls Mach3's implementation of constant velocity moves
to suit the characteristics of plasma cutters. It does anti-dive and tries not to round corners in some cir-
cumstances. For the most part, ArtSoft USA suggests you not select this option unless your machine
has very poor acceleration and poor step resolution.

The one part that matters to you and why you can not see any differences

• Only licensed versions can enable THC mode.
That goes counter to what I thought I understood about Mach3 licensing. It was my understanding that the only thing that was limited on a "demo" version was the number of lines of code it would accept (180). Never-the-less, I won't be acquiring a license anytime soon as I just laid out over $4000 to purchase a functioning plasma cutter and an additional air compressor to feed more air into it. If someone thinks they can squeeze another $150 out of me to license a piece of software that is no longer supported by the publisher then perhaps I could interest them in a little piece of ocean from property I own out in the Sonoran desert in Arizona.

I've read what ever documentation I could find re. Mach3 and there is little or no info re plasma cutting in it; certainly not enough to answer any of my questions. In fact, that is the first thing i did weeks no months ago. That is why I find myself here begging for help (I do appreciate, very much, the help that has been offered!)
AdrianH wrote:So unless I get better a higher res screen/Graphics card I can not get in the screen set to see what dro's tags etc has programmed into them, sorry.

Hope you get an answer from the guy on Mach.

Adrian
Thank you for trying regardless. I hope I get a response as well, but I'm not going to hold my breath. I'm toying with the idea of migrating over to LinuxCNC. From what I've seen, and apart from the fact that it's free, it's much more actively supported than Mach3 with greater capability to boot. No doubt there will be a steep learning curve involved, but in the end I believe it will be worth it.

There are many functions that I would like to attempt to integrate into whatever control software I am using to cut plate and the LinuxCNC API seems to be much more open and available with developers of all levels working to improve it. Mach3? Not so much.
AdrianH
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Re: THC Issue with Sheetcam and/or Mach3

Post by AdrianH »

At some point in time I would like to get over to Linux EMC or what ever it is called now, but its the learning curve again.

Sheetcam is the one that only gives 180 Lines of code in non licensed mode. Mach3 the THC stuff.

Have fun.

Adrian
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Re: THC Issue with Sheetcam and/or Mach3

Post by islander261 »

Guys

I don't want rain on your parade but I think you need a serious reality check about using LinuxCNC to control a plasma table. There is no canned plug and play open source solution plasma table configuration available to just download and go. There is a very small core of people actively involved in plasma solutions and most of them are focused on systems that are as complex as the proprietary solutions. There are several proprietary solutions based on LinuxCNC that you can get when you buy their hardware. If you have a gantry table with dual drives it gets even harder right from the start if you want automatic gantry squaring on homing ( are you good at downloading source code files and compiling in Linux?). If you plan on using a Proma or similar external THC then you at least have a chance because there are several configurations floating around that use these.

So, a short story is called for here. Myself and at least one other I know of that do plasma cutting thought that LinuxCNC would be the easy way to go to get a really full featured industrial scaled solution and have it open sourced so you aren't dependent on vendor upgrades and new Windoze versions with automatic updates. After all there are a number of plasma configuration examples as part of the standard package right? Well once you dive in you will find that the plasma configurations are just pretty screens with none of the backend code (Python, .hal files)connections to hardware made (ready to roll your own?). After 2 1/2 years I still don't have a production grade system working. I am actually very close to a working solution with integrated THC and use of external tool libraries. I have cut between 100 and 200 test lines getting really good THC performance worked out. I am now at the last step which is getting a good robust SheetCam PP worked out to go with my system. And yes along the way I did have to buy proprietary hardware (Mesa) because just using the parallel port with a BOB doesn't cut it if you want to do advanced THC inside of LinuxCNC. I cut almost every day with my old TM2 controls, yard and interior decorative art, so I am no stranger to running a cnc plasma table. One other thing, standard Linux will not run LinuxCNC, you have to use a kernel with realtime patches. This isn't such a big deal if you happen to have relatively standard late model computer hardware because there are prepackaged patched distros for both Debian and Linuxmint (Ubunto) available. If one of these will not run on your hardware then you will have to compile and patch your own kernel, a task not for the feint of heart.

Go over to the LinuxCNC web site and download and read the documentation, do you understand what you are reading? Go to the forum and read about peoples experiences with plasma systems (over 98% of the forum topics are about mills and lathes). Get really good at using the forum because you will need it for help! Good luck, you can do it but it won't be easy.

John
AdrianH
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Re: THC Issue with Sheetcam and/or Mach3

Post by AdrianH »

Hello John;

I thank you for the insight, I have used Linux at home for years now and it has never been a good plug and play solution unless some of the experts have been there before and written the .rpm's first.

I use Suse which I think is still backed by Novel. I have downloaded EMC as it was, EMC2 as it became and have a copy of something now, I use one of my back up computers that already run Linux to run the live disk and think my word, even some of the terminology seems foreign. The numbers to test hardware do not always give good results with recommendations saying you should run external graphics cards etc.

So yes I agree with you in that it is not yet a good system to use in a production environment without having some serious back-up or programming skills.

There does seem to be one that springs to mind tcaudle that (hope I got that correct) and a few others running commandcnc that have been in it for years have taken the time to put together systems that they then sell and support.

The general thought that one can start off in plasma, by buying or building a table, just add a plasma cutter and a bit of software and jump into commercial high quality production, is in my view a non starter.

There is the other side of the coin, the ones I guess like me, could never justify the price of a commercial system, wish to do bits of art stuff, gradually learn as they progress, keep tinkering, trying settings, and gradually will know enough to consistently get good cuts at the end of the job. 3 years for me now and I am still learning, added new cutting rules after learning how to use M10P1 etc. only recently.

When I have an issue I can generally figure it now. If I can help others I try my very best. Eventually I will put my knowledge to build a better table and start again possibly on a bigger scale. For me Linuxcnc will be the challenge, but in program THC with PID control and servos and all the bells and whistles will probably still be outside of my not so deep pockets.

So expect me to pester you at some point, or anyone else for that matter, as one day I will connect another PC to my table and try and replicate Mach3 features.

Does one still need the Real time Kernel?

Adrian
tcaudle
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Re: THC Issue with Sheetcam and/or Mach3

Post by tcaudle »

LinuxCNC is a "framework". Its a raw set of tools that let you build whatever you want. Best analogy is it's a full set of carpenter tools and some instructions on how use them but the SKILLS to actually build something of significance is up to the users level of talent and patience. It can be made to do almost anything you want and look any way you want. Its been used to build all types of machines. If your goal is learning and to meet a challenge you can swap time for money and build your own (just like your own furniture with carpentry tools) . If your goal is to run and cut and make money there are off the shelf LinuxCNC/hardware solutions for plasma that will run circles around any MACH based system.
islander261
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Re: THC Issue with Sheetcam and/or Mach3

Post by islander261 »

Adrian

Even the most basic LinuxCNC system with an external THC ( CandCNC actually uses a proprietary external THC that uses a serial connection to the main Linux part) will run circles around a Mach3 system. Yes you do need a to use a realtime kernel to make it work. Get a late model spare PC and try and install one of the prepackaged distros, if you are lucky it will work on your hardware. I like the Linuxmint (Ubunto) flavors myself. Good luck, this is the future.

John
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Re: THC Issue with Sheetcam and/or Mach3

Post by jawneelogik »

jawneelogik wrote: I'm toying with the idea of migrating over to LinuxCNC. From what I've seen, and apart from the fact that it's free, it's much more actively supported than Mach3 with greater capability to boot. No doubt there will be a steep learning curve involved, but in the end I believe it will be worth it.

There are many functions that I would like to attempt to integrate into whatever control software I am using to cut plate and the LinuxCNC API seems to be much more open and available with developers of all levels working to improve it. Mach3? Not so much.
That sho nuff seems like it struck a chord! Y'all seem to have a bit of a love/hate thang goin on fo Linux! Hey, it's just software. And, it's software that, at least someone is still working on. It's not crippleware.

The guy who claims the role of author of Mach3 tells you to try his software, but forgets to tell you, "Oh, BTW, until you pay me, the functions that are most important to what you are trying to do are disabled. Go ahead and waste months of your time all the while looking like a complete moron in front of your customer. Oh, and BTW, we don't even support that version any more. And, BTW, how 'bout I raise the price of that same unsupported software another $25 just for good measure-- just because."

I'll endure the learning curve thank you. I always have and believe it's made me a better person. Thanks for all the input. I have learned from it.
Rodw
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Re: THC Issue with Sheetcam and/or Mach3

Post by Rodw »

As John (islander261) says, Plasma support in LinuxCNC is quite immature yet you have guys like tcaudle who have migrated their commercial systems to it. That could not have been a trivial project. The hardware is there, but it has not been integrated into a public working system. To be fair, John and idiots like me have been playing with an experimental development branch. There is a European manufacturer making a big effort to adopt LinuxCNC and it would be nice to hope that some of his work migrates in to the code base. IN the long term I'd like to think that external THC's like proma et al are rendered obsolete in preference for internally managed THC functionality controlled by LinuxCNC's trajectory planner which Jim Colt keep reminding us is the best practice for plasma. John's got it working, I've had some promising results as this video shows but we are not quite there yet.

https://youtu.be/uUE_rU_GlPs

Unfortunately, we are all individuals scattered all around the world rather than being part of a coordinated development team. But each of us will crack it one day.
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