Advanced Search

Hi there, 
I implemented an DIY Arduino a few weeks back into my automatic injection molding machine. So cool to see that topic popping up again!
For the background, I have two CNC machines running on LinuxCNC as well and I am familiar with some Arduino-Coding too.

In the beginning I evaluated the exact same question as you here and went with the Arduino based PLC-Route as it is easier to implement hardware and manage timers easily, which there are a lot of in injection molding as many events in a cycle are time-based.

A few lessons learned so far were:

• The evaluation of "Readymade" ESP32/Arduino resulted that there is no real all in one provider like Beckhoff Ethercat modules. That drove me away from it as you still need additional "raw PCB boards" for e.g. temperature input. Then "real" PLCs like Ethercat are freaking expensive if you need anything but standard IOs. Could be an option if you base everything on second hand components!
• These modules are really nice: sequentmicrosystems.com/products/eight-t...bj3cF5BPXDmnSfa68zMp
  They are a bit more expensive then a MAX31855 etc. but a very clean solution, easy to install and you can just stack it on top of a Raspberry PI. And are very well documented too + some Libraries exist. Not affiliated with them, just made a really good impression!
• Having temps all in one controller is nice for process debugging
• Used Breakout boards as Optocouplers, SSR Output boards (240V AC 1-2A), external SSRs (40A) and DC Relay boards (24V) and the Temp input board of Sequent Microsystems.
  To be honest I would next time spend a bit more with Sequent Microsystems - they seem to be fairly well priced and offer a lot more IOs and flexibility then the "All in one" Arduino based PLCs. But if money is a big constraint you can go with the single modules too.
• I prefer SSRs just because they are silent, and basically free today and never had a cheap Asian branded fail
• For the IO side Arduino is pretty nice and fast as it is easy to connect components and debug them. E.g. for installing a linear scale I did not need a Mesa card or other boards just connected it to an interrupt and fed it to an existing Library.
• I used BlockNot to create parallel tasks, such as asking for sensor states at fixed intervals, have interrupts for linear encoders, run all the cycle timers... that is a very cool lib to work with!
• Okay now the butttt...
  As soon as you want to build an GUI for it it becomes annoying. Maybe its my lack of experience for it or I am not aware of better solutions. Let me know if anyone is aware of a similar GUI solution to LinuxCNC (in flexibility) but for simple controllers?!
  I tried to use Nextion Displays - which are displays with their own IC. That is cool as they mostly run smooth without Display lags in comparison to other solutions and have a GUI editor. 
  The pain is that you need to manage the whole communication between the display IC and the IO-IC (e.g. Arduino) manually. Eg. read button pushes from the display and feed data back. That is not impossible but a ton of (unnecessary?) work. Additionally the GUI modules come with good limitations in all directions- e.g. you can only have 4 data inputs into a diagram display which is already limiting on e.g. temp tracking. The graph you get is also not really useful in manner of navigation as zoom/ set scale etc. There are many things that need to be build to get something usable.

So I got stuck and ran it from basically a serial console + manually edition code for changes. That kind of works for home/DIY but is not a "solution" I would say as I run this machine for work. Okay that is a bit funny, but its actually some kind of special setup that does not exist on the market.

So my position is that I have a working machine, but no real interface.
I consider now to mange all the IO's by Arduino as nothing is really time critical and the linear encoders in my app don't need to be updated to the GUI in real time. You can also mix both options and use a motion card like Mesa or a simple Breakout card for motor control and safety IOs and do the rest with an external "PLC". 

Some strong points for LinuxCNC in this application:

• Easy to build GUIs
• Real time IO's for motors+safety
• ShowHAL+HalScope is priceless for real-time debugging of states, that would need to be programmed as special IO's otherwise
• Settings can easily saved in files - I would miss-use a .nc file to save projects, temps and timings?

Weak points for LinuxCNC in this application:

• Calculations and conditions are just painful as you need to do everything with components, which would be a simple calc sign otherwise :/
• Not sure how to implement a nice cycles with timings? Could be several timers connected to each other! Would be cool to be able to activate/deactivate these in real time on GUI input to control auxiliary devices.
• Is there an option to use e.g. the HalScope inside a GUI? Or have another graph implemented?

Let me know your thoughts and considerations, happy to exchange ideas here!

That's a windows splash screen, not a splash screen when booting a Linuxcnc install disk.

Download this program and install, after reading the whole page.
win32diskimager.org/

When you insert the USB stick you want to make a Linuxcnc bootdisk don't let windows do anything if it cant read your USB stick, windows does not be able to read the USB stick.

Run the Program you just installed.
Select the image, the image you have confirmed the md5sum is good, if not download it again and check again. I'm not a windows user so you'll have to search how to check the md5sum under windows. Also select your USB drive, do not select a hard disk.

Write the image to the USB stick.

If windows complains about not being able to read the disk DO NOTHING. Everything is ok.

Reboot the computer and select USB boot. If you are going to install make sure you have enough space on your disk or have an unused disk available for Linuxcnc.

I recommend this tool as all it does is copy form the image file to the usb stick byte for byte. It doesn't try to be fancy, it does exactly what is required to create a bootable USB Stick from the image.

I got past that. It attempts to boot from USB drive but this is as far as it goes.  See attachment. 
 

Okay. I am using Rufus but it does not like the ISO. The complaint is "the ISO you have selected contains a UEFI bootloader that has bween revoked. and that will produce a "Security Violation" screen. Rufus suggests a more up to date ISO. linuxCNC 2.9.4 is not current enough?

Can you post your config files?

You should have mentioned that, could save me several minutes of typing !
You are welcomed, always.

Long story short, a lot of things were changed before I replaced the the 7i97t. Since then, I have have been cutting with zero issues. The thcad for arc volts is reading accurately while cutting. The thcad for ohmic is not hooked up. I can't get it to work, but maybe that's a good thing because it sounds like it's a bad idea with hf start.

The longer story is that this machine didn't have a home. So while its new home was being built, I set it up temporarily in my shop, so I could attempt to retrofit it with linuxcnc. When I fired up the torch for the first time, it damaged the 7i97t. This was with both ohmic and arc volts hooked up, so its anybodys guess what caused it. I added some grounds and an emi filter and few other things then replaced the 7i97t. Then I got it working great with a non hf plasma(except I didn't hook up ohmic).
Then after it was moved into its new home, we added several ground rods and hooked it up to the hf start plasma the way you had just advised. It's been cutting great. 

I know I ask a lot stupid questions but I do appreciate the help. 

Its an Ethernet card, i got the motors to spin as though it were a milling machine, but SCARA isn't an option. The default it has is XYZ, XYZA and XZ lathe, none of those options are what i need. I followed a few guides that said how to change the kinematics but so far, following those guides, I've had no luck. I was hoping that might be able to helps me out with either more direct communication or by providing a working example.

If there was a "known problem" it would have been fixed pretty quick.
The guys that build the ISO test them, they aren't just built and thrown out into the wild, things just don't work that way.
Usually in these kind of issues the first port of call should be to check the download as tommy suggests, rather than just assume it's a problem with the way the ISO has been built.

Is there any reason you cant boot from a USB drive ?

It helps to burn the DVD at 1X speed, if at all possible, as it lowers the write errors.
I would also check the manufacturing date on the DVD box, fully enclosed they can be OK for 5 to 20 years depending on moisture in environment, hermetically sealed even more.
Did you check the MD5SUM or SHA256 for the download? It can also be a bad download due to interruptions or drops in connection.

It comes down to what pinout you need.

What is the 7I92T connected to?

That is, what breakout board are you using?


 

I burned the 2.9.4 ISO to a DVD.  Because my DVDROM drive went bad recently, I bought a replacement.  Amazingly, I found an exact match for my Dell Optiplex 960.  It plugged right in, passed diagnostics and successfully booted from DVD.  I went a burned it again.  Same problem.  Is there a known problem with the release ISO, or does Windows 11 ISO burn just not work?

I downloaded the archive for mesa 7i92t cards from the official website, but there are so many different firmware versions that I don't understand which folder I need to copy.

The thing is, I don't know how to do it))
This is my first time doing this, and I'm already panicking because I've been trying to figure it out for over a month))) Now I've decided to ask people for help!))
My LinuxCNC doesn't have any firmware for Mesa 7i92TH at all.

mesaflash 3.5.16 is the latest

If you want 4 stepgens and 4 encoders, what pinout do you want?

(If for a 7I85S you would use 7i92t_7i85sx2d.bin = config fir 7I85S with 4 stepgens, 4 encoders, 1 sserial port per connector)