Controller Advice Needed

[joeavaerage]

Hi,
did you load and install a Linux distro with RTE?

You absolutely MUST have a realtime distro.....otherwise LinuxCNC is a no go. I seem to recall about six years ago the distro of choice for LinuxCNC was Debian with RTE.

I think the bottom line is that your machine controller should do that one job alone otherwise your asking for trouble. It was once explained to me, in reference to Winodws PCs,
'that once you use a PC to control a machine it is NO LONGER a general purpose computing platform but a machine controller that just happens to use Windows as an OS'.
I have applied that policy ever since. My machine PC runs Mach and a couple auxiliary programs related to running Mach. Its not connected to the internet EVER. It does not have
a firewall, I don't just mean turned off, I mean NOT PRESENT, likewise no anti-virus, not just turned off but ABSENT.

I would strongly recommend that you have a PC for your machine and that it does nothing else, even a network connection is frowned on in some circles.

My machine PC is a dual core Atom mini-ITX single board PC with on board graphics and 3G Ram which is shared with the video. In short a VERY low power PC, way less than recommended
by NFS for Mach4 but it runs perfectly thanks very much. Its a bit slow to load large Gcode files and slow to draw the initial toolpath but thereafter its perfect. The bottom line is that you don't
need a powerful PC just one that sticks to the job in hand. A powerful PC might load and do the initial draw somewhat faster but the machine will go NO faster, NO more accurately, NO more
anything. Just get one of the grandkids cast off PC's load a realtime Linux distro and LinuxCNC and you'll be golden.

Craig

[joeavaerage]

Hi,
you could of course buy a Fanuc21 or a Seimens 840, then you wouldn't have to fiddle around with a PC, a motion controller or anything.....just pay your $20,000 plus
and you're set for life, except those pesky annual license fees!

Craig

[dazp1976]

Hi,
I think the bottom line is that your machine controller should do that one job alone otherwise your asking for trouble. It was once explained to me, in reference to Winodws PCs,
'that once you use a PC to control a machine it is NO LONGER a general purpose computing platform but a machine controller that just happens to use Windows as an OS'.
I have applied that policy ever since. My machine PC runs Mach and a couple auxiliary programs related to running Mach. Its not connected to the internet EVER. It does not have
a firewall, I don't just mean turned off, I mean NOT PRESENT, likewise no anti-virus, not just turned off but ABSENT.
I would strongly recommend that you have a PC for your machine and that it does nothing else, even a network connection is frowned on in some circles.
Craig

Same as.
I used to enable the wifi card solely for gcode transfers then disable it again.
Now I just use my usb sticks.

[routalot]

I wouldn't use a Windows machine for any task beyond running the machine if I had a Windows based controller,but I use LinuxCNC with wifi enabled and it has been 100% reliable.The established preference for just giving the machine a single function was a lot more valid in the days of Pentium 2 chips but more modern machines have so much more capacity that isn't being utilised that it doesn't seem to impede the performance of the machine if I carry out other tasks or listen to online radio.

[dazp1976]

I wouldn't use a Windows machine for any task beyond running the machine if I had a Windows based controller,but I use LinuxCNC with wifi enabled and it has been 100% reliable.The established preference for just giving the machine a single function was a lot more valid in the days of Pentium 2 chips but more modern machines have so much more capacity that isn't being utilised that it doesn't seem to impede the performance of the machine if I carry out other tasks or listen to online radio.

It's mainly all about viruses and bugs.
As soon as you connect a pc to the internet, it's bugged.
That's how the web works these days.
Kept off-line, The pc will never need reinstalling until it actually dies.

I could watch movies, wifi surf, music, docs, etc while cutting with no issues at all.
I had to reinstall twice one year because of minor glitches cropping up.
That was 2018.
Since it's been off-line it's still perfect after 3 years.

[routalot]

I can understand that,but I haven't had to reinstall ever.Perhaps it helps that I activated the firewall in my router and don't go anywhere near social media,this being as close as it gets.My other Linux machines have also functioned without any hiccups although one has an active additional firewall due to some personal data being present.

[dazp1976]

The more I look at the Mesa cards now. The more intrigued I am.
If I hadn't gone down the road I have done, I'd have played around with Linux to see if I could get a feel for it.
Even though I'm in the u.k. I'd have prob lived with the import costs.

For what I'd 'like' to build...
Like the look of the 7I80HD (or 2) and then at least 3 daughtercards. However...

The 7I94 says it's almost unlimited IO and looks like they have loads of daughter options for it via RJ45..
Servo drives, encoders, ATC, pwm, pendants, sensors everywhere.... Sounds bliss and they look to be fairly compact in size.
(Prob at a large cost too).

[Project_Hopeless]

The more I look at the Mesa cards now. The more intrigued I am.
If I hadn't gone down the road I have done, I'd have played around with Linux to see if I could get a feel for it.
Even though I'm in the u.k. I'd have prob lived with the import costs.

I love my Mesa Card (7i96e). Step control, I/O, PWM spindle, Ethernet, all one small card.
.

[Sray]

I have had some problems over the years with Linux but usually after I do updates. Especially kernel updates. I have been able to fix most of the issues but there have been a few that I was unable to recover from and had to rebuild. But nowhere near the problems I have had with Windows. Although W10 had been very solid. But I still would not want to run a CNC from it. Too many processes and **** going on in the background. And always being forced to do updates and changes that Microsoft thinks I need.

Anyway, I was finally able to boot up into the usb live version (LinuxCNC 2.8.2 Debian 10 Buster PREEMPT-RT ISO) of LinuxCNC. I ran some latency tests and the numbers don't look great but I think it may be within tolerances. I most likely will put together another PC or buy one to run it anyway.

[joeavaerage]

Hi,

Although W10 had been very solid. But I still would not want to run a CNC from it. Too many processes and **** going on in the background.

Rubbish, tens of thousands of users are machining with a Windows10 platform. Windows 10 Pro allows you to turn off updates....and if you follow what has already been said
it should not be connected anyway....no matter what.

I most likely will put together another PC or buy one to run it anyway.

\
This was inevitable whether you go with Linux OR Windows.

Craig

[rodw]

With what I read, you are running steppers on a machine with a spindle.
In that case an ethernet Mesa 7i76e should be perfect for you.

What I don't think has been made clear is that Linuxcnc IS_THE_MOTION_CONTROLLER.
A real time OS is required to guarantee things happen on time. Fortunatley the PREEMPT_RT real time kernel is now available in the repositories for many distros
With Mach3, the Motion controller today is the ESS card or equivalent.
A full blown PC has far more CPU power than an embedded controller.
If you use a parallel port with Linuxcnc, the step generation is done on the PC in software which limits the maximum possible stepgen frequency.
What the Mesa cards do is offload the step generation to external hardware at frequencies up to 10 MHz. The motion controller just needs to tell the card what frequency to generate and it can change that 1000 times per second.
The offloaded step generation then substantially reduces the latency requirements so a greater range of PC's ca be used..

Linuxcnc is much more complex and extensible than its Widows competitors and a greater range of hardware is supported. Accordingly, some people find it more complex to configure.

I have recently helped someone to configure some Ethercat drives with Linuxcnc. To do this with Mach4, he tells me it was a USD $2800 spend. The Ethercat Master software is open source on Linux and can be integrated with Linuxcnc. Needless to say, I have some ethercat drives coming...

[joeavaerage]

Hi Rodw,

To do this with Mach4, he tells me it was a USD $2800 spend

There is only one company offering Ethercat and Mach4, and yes it does cost $2800, but that includes the Mach4 license, the RT64 (realtime kernel for Windows) runtime license, and three 750W AC Ethercat servos.
Strictly speaking Ethercat master is free, the license is paid as part of the cost of the IC required for a slave device. Thus each of the servo drives has one of these ICs and so the Ethercat license is paid when you buy
the IC. The ICs are about $10 each including the license fee....hardly excessive.

Craig

[rodw]

Hi Rodw,



There is only one company offering Ethercat and Mach4, and yes it does cost $2800, but that includes the Mach4 license, the RT64 (realtime kernel for Windows) runtime license, and three 750W AC Ethercat servos.
Strictly speaking Ethercat master is free, the license is paid as part of the cost of the IC required for a slave device. Thus each of the servo drives has one of these ICs and so the Ethercat license is paid when you buy
the IC. The ICs are about $10 each including the license fee....hardly excessive.

Craig

I'm only reporting what I was told. He already had the drives so I don't think they were included. Certainly motors are a seperate listing on Vital's site. Good luck buying a $10 chip and making your own slave device. Commercial slave devices are not cheap.

But Ethercat with Linuxcnc is not for the faint hearted as its not well documented. I got some pricing from Beckhoff Australia on Friday for I/O addons (encoders and analog inputs). Adding an encoder input would cost AUD $1k

For home builds the Mesa 7i76e is really a no brainer for a machine with a spindle. 5 stepgens, 32 inputs, 16 0utputs, 4 analog inputs, 2 MPG inputs, encoder input and 0-10v spindle control are all supported. Plus room for 2 more daughter cards (15 axis anyone?) plus a RS422 smart serial interface for a whole range other devices. eg the 7i73 would allow you to build or retrofit a whole HMI interface.

[Sray]

Rubbish, tens of thousands of users are machining with a Windows10 platform. Windows 10 Pro allows you to turn off updates....and if you follow what has already been said
it should not be connected anyway....no matter what.

That is great. MS has definitely upped their game. My experiences over the years with Windows was a love/hate relationship. I spent way too much time and money just trying to get things to work. Been burned too many times. But like I said, Windows 10 has been a good experience so far.

This was inevitable whether you go with Linux OR Windows.

Yep. I was just hoping I could get things up and running on my laptop and then upgrade later. Fingers crossed!

[Sray]

For home builds the Mesa 7i76e is really a no brainer for a machine with a spindle. 5 stepgens, 32 inputs, 16 0utputs, 4 analog inputs, 2 MPG inputs, encoder input and 0-10v spindle control are all supported. Plus room for 2 more daughter cards (15 axis anyone?) plus a RS422 smart serial interface for a whole range other devices. eg the 7i73 would allow you to build or retrofit a whole HMI interface.

Yeah it seems to be a good starting point.

[dazp1976]

For home builds the Mesa 7i76e is really a no brainer for a machine with a spindle. 5 stepgens, 32 inputs, 16 0utputs, 4 analog inputs, 2 MPG inputs, encoder input and 0-10v spindle control are all supported. Plus room for 2 more daughter cards (15 axis anyone?) plus a RS422 smart serial interface for a whole range other devices. eg the 7i73 would allow you to build or retrofit a whole HMI interface.

What about if you decide on servos though?
I figure for 4 servo motors (proper AC ones). You're looking at 16 inputs for encoder and index points, and 5 to 6 inputs each for fault signals.
This is why I suggest to look ahead. If the ultimate plan is for servos eventually then save yourself money and get the capable electronics now. Then you only have to change a few things later on rather than everything.

If the plan is just to stay with steppers on said machine then something like a Mesa 7i96e or 7i76e is prob plenty.

[rodw]

What about if you decide on servos though?
I figure for 4 servo motors (proper AC ones). You're looking at 16 inputs for encoder and index points, and 5 to 6 inputs each for fault signals.
This is why I suggest to look ahead. If the ultimate plan is for servos eventually then save yourself money and get the capable electronics now. Then you only have to change a few things later on rather than everything.

If the plan is just to stay with steppers on said machine then something like a Mesa 7i96e or 7i76e is prob plenty.

If you were to go with servos, you might choose a different Mesa card. If the encoder feedback loop was closed in a step/dir servo drive, the 7i76e is still probably OK, but you could choose a 7i95 which adds encoder inputs to the step/direction interface. If you were retrofitting older hardware with 0-10 volt servos (or were using cheap Chinese servos) You could use the 7i97. So many options its hard to keep up with what Mesa offers.

[dazp1976]

Rubbish, tens of thousands of users are machining with a Windows10 platform. Windows 10 Pro allows you to turn off updates....and if you follow what has already been said
it should not be connected anyway....no matter what.
This was inevitable whether you go with Linux OR Windows.
Craig

I'm still on Win7.
Have retail discs from years ago.
All I need to do is update SP1 and some .net framework (all of which I keep on file) and that's it.

Works excellent with my UC300eth- UCBB- UCCNC.

Am looking to getting a cheap laptop to run it from to save on power use. Like a Dell E5430 or something.

[routalot]

Hi Rodw,



There is only one company offering Ethercat and Mach4, and yes it does cost $2800, but that includes the Mach4 license, the RT64 (realtime kernel for Windows) runtime license, and three 750W AC Ethercat servos.
Strictly speaking Ethercat master is free, the license is paid as part of the cost of the IC required for a slave device. Thus each of the servo drives has one of these ICs and so the Ethercat license is paid when you buy
the IC. The ICs are about $10 each including the license fee....hardly excessive.

Craig

I'm amazed at the $2800 figure.The Dell Optiplex that controls my hobby machine cost about 1.4% of that and it includes the monitor.I suppose the desire to stay with Windows is what has made Microsoft the most valuable company in the world.

[JohnZ]

That is all excellent information (post #76 above) Craig for the OP and for all reading this thread for what is possible to achieve.

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