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In my opinion, some model RPIs (4 or 5) are capable enough to make a control using Linuxcnc, but a PC will generally make a more robust and reliable system, and probably not cost significantly more.

The 'pncconf' configuration tool does this automatically.

If you want to check the `P` values in the ini file against the `SERVO_PERIOD` then this might be something that a GUI could do on start up followed by a message pop up in the GUI.

I frequently use the run pause..run from here feature...not sure if that exposes the weaknesses

Seems to be getting worse...

Nice to hear, I'm glad it was helpful.

   I have a new build project coming up and I need a 7i76EU for the build. But as my luck
usually runs Mesa Electronics is sold out of them. Does anyone know when more 
are expected to be in stock?

Hello, Aciera
After reading the paper you sent, I gained a lot of insights. Based on the method described in the paper, I successfully derived the kinematics that fits my machine tool configuration. Currently, it has been successfully implemented on my machine, and no other issues have been identified so far.
Lastly,thank you very much for your help!

Hi Group

I would like to potentially use linuxcnc on a Raspberry Pi to program and test steppers and servos

• Are there any solutions that I can see samples of or potential uses that are using a Raspberry Pi or Arduino and LinuxCNC to control and test servo and stepping motors?
  
• One plan is to have a test bench to play with ideas; this will have a controller board, some switches, sliders, connectors for motors, a variable power supply, etc..
  - Could LinuxCNC be used for this? i.e can i program it with Python or similar to run my code snippets or a full program?
  - When connecting motors that use pulse and direction, will I be able to connect any motor as long as the variable power supply is adjusted to give the right power to the motor?
  - Has anyone done this before like this?
  
• Another plan is to create individual builds that will have one or more motors, sensors, switches, etc.. and will be all built into a case or item as a stand-alone solution. With a customised touch control screen. So when powered on, it boots up and is ready to use and be controlled from the touch control screen.
  can linuxCNC be used like this?
  if so is ther any links to videos or projects that do similer?
  
  Z
  
  

hi Group

I just purchased a boxford 250pc lathe in a hardely used immaculate condition; however, as per the norm, it has no brain and the internal electronics, although pretty much unused, will be changed over to new stuff so I eliminate any issues and get going properly first time.
I will then likely use all the removed bits for other projects.

• controllers
  At the moment, I am considering LinuxCNC, Mach 3/4, poss arduino,  and Centroid Acorn
  So can anyone advise if LinuxCNC on a Raspberry Pi will be powerful enough and good enough to use on a Boxford 250PC lathe with 2-axis, a tool changer, homing limit switches, spindle encoder with z values for threading, spindle speed control, a pump, E-stops, and the potential for another two-axis as well?
  
• I like the idea of Raspberry Pi as it is small, adaptable, and can be built into cases, etc.. but would I be better off using a PC?? 
  or is the Raspberry Pi the way to go?
  or will Arduino be even better?
  
• I am pretty good at doing stuff, and learn quickly. I have had some experience programming steppers from an Arduino before, but with LinuxCNC is there lots of help information available on the web and youtube etc, and is the forum friendly, helpful, and resourceful when needed?
  
• What does the linuxCNC use for lathe control software (i.e like mach 3/4 or centroid CNC12)?
  Does it work well?
  is there any links to see it in action on YouTube?
  can it be messed about with to map out the control screen as i would like?
  Can the control screen running the lathe control software be used in portrait mode on a reasonable-sized screen?
  
• With LinuxCNC on a Raspberry Pi, are there any limits to motor sizes in both stepper and servo motors?

I look forward to any input/feedback

Z

A quick Google indicated your motherboard is a poor choice for PREEMPT_RT kernel due to Its aging AMD 760G/SB710 chipset, older BIOS/ACPI implementations, and high System Management Interrupt (SMI) jitter typically cause severe latency spikes and potential system instability under hard real-time workloads.

I've never been keen on AMD.

Yaaaay!

Oh yeah, no need for virtual machines, this is Linux, so download the ISO, write it to USB using Balena Etcher or DD or image writer on Linux, boot from it in Live mode, test as much as you like, reboot and remove USB, it does not write nor change anything to existing hard drive.
And also you can actually run machines while in Live mode.

saxa wrote:

By "leave them out" I meant to not connect them at all. But then how the linuxcnc will know where it is at certain point ? I will probably loose a part of precision with not connecting the encoders feedback.

Yes, do not connect the encoder output from DMM drives to Mesa board, see below

saxa wrote:

I see this card has a DB25 connector to connect it to the computer I suppose, or does it gets connected to the
7i96s ?

It gets connected to Mesa board, and yes it looks like parallel port, and yes there are adapters that connect to Mesa 7i96S (and other Mesa boards) that work as parallel port but at much, much higher pulse speeds, and no 7i85 can not be used with a normal parallel port.

saxa wrote:

Is the DMM Dyn4 encoder output supported by the Mesa 7i85 ?

Yes it is, and yes it works fine, technically, in reality the DMM drives have some strange latency/delay issues that make them useless for real time feedback.
But they do work fine (from what i read here) when used as normal stepper drives with step/dir control, and yes the precision will be out of LinuxCNC reach, but if the drives are tuned properly that should not be an issue.

Did it get worse with time, or is it roughly the same?
-
Stuff you can test:
-open a terminal while LinuxCNC is open, does not have to be enabled or running, type "sensors", check temps
-remove the CPU cooler and apply fresh thermal paste
-remove memory sticks if more than one and test, one by one. Do remove power and wait 2 minutes before removing or inserting modules.
-boot from USB stick containing LinuxCNC in live mode, run LinuxCNC, does it freeze?
-
Other things:
power supply
drying capacitors on PSU or motherboard
if you are using serial or usb for comms to machine, remove and test without them

Hi...I have an older MSI Motherboard 7641 ver 1....using mesa 7i96s for 6 axis work..recently more frequent freezes...read only errors or crashing..Today I noticed it happened immediately after selecting live plot....I know it could be a lot of things only related to pc but I am curious to see if there is any known causes to look into before changing parts etc...Using debian bookworm

Thanks,

Rick