Modern/compact linuxcnc setup

Hi everybody, I planning to switch my diy compact milling machine to linuxcnc.
I have done quite a bit of initial research, I even spent days to get rtai to build on buster, only to finally discover that there are secret pre-built deb packages in /temp...

I am interested in what would be an ideal setup if you had to start from scratch and wanted a reasonably compact setup.
An example could be itx case/motherboard + parallel port breakout, or maybe raspberry pi + ethernet mesa card.

Any idea on what would be the most supported or ideal setup?

I am currently using steppers with encoders and closed loop controllers and I am considering eventually upgrading my axis to linear encoders.

Thanks for the help!

this is all up to You
AND ofcause your Budget
if you can affort it then go for a MESA 7i76e or lower cost a 7i96
This gives you the most benefit
the PC is a glimp of interest as you only need a low cost but big standad
THe machine shoudt run on its own System not as a Full running desktop use

Why not starting with a ISO DVD redy to run within 1hr of install to your machine

If you go the Pi route either the Mesa 7c80 or 7c81. May go this way for the lathe.

For "future proof" I went with a Mesa Ethernet setup using an ITX board.
I started with a 7i92 intending to use a "std BoB" but then rethought things and went with a 7i76 as well. Recently got 7i73 for a Pendant and future control panel.

ATM I have the ITX in a 1u rack enclosure, Mesa cards & related PSU's in a 2u rack enclosure and stepper drivers & 48 psu in 3u rack enclosure. Sounds a bit OTT but I can slide the Mesa unit out to work on outside of the workshop. Probably not what you would call compact. TBH I stated with the 3u enclosure about 5 or 6 years ago when I was using Mach3 and the PP with another machine....... Kind grew over the years.

If going Mesa there is an install disc for Linux Mint 19.2 ie only RT atm the moment. Will look into RTAI shortly. Take note to either use dd under Linux or win32diskImager under windows to get the image onto USB or you can just burn it to DVD.
forum.linuxcnc.org/9-installing-linuxcnc...tion?start=90#157109

I've looked around and unfortunately there are not many mobos that come with a parallel port today.
I could only find ASRock j3455b and noticed that a lot of people are having flash related bios problems.

I run a Asrock J3355B-ITX wihch has a on board PP, tho I do use Mesa cards.
Never had an issue.

Guys, thanks for the advice.

bbsr_5a: budget is not unlimited but I'm also not worried about spending 100 bucks more for a better setup (it only has to save a couple of good end mills over it's lifetime to pay itself back

BeagleBrainz: thanks for the details. If I go with Mesa (either Ethernet or SPI) I'm I right to assume that I won't have to worry too much about base thread latency and I could probably be ok with a preempt-rt setup? If I don't have to worry too much about getting rtai to be happy I'm less concerned about going with a pi setup (not sure how well arm support is).

I'm pretty convinced Mesa is the way to go, mostly because it's hard to find small mother boards with parallel ports.
Between Ethernet and Pi SPI, what would be the best interface?

In all honesty I'd run with a std PC setup with Ethernet. Latency, with in reason, is not such an issue with the Nesa Ethernet boards.
An RPi4 would probably work with ethernet as well as it's on the PCIe bus now and not on the USB bus.
An RPi with Spi works to all accounts, but, and this is not a slur on the Mesa gear, I think Ethernet will still be with PC's for a while and is an option for the RPi. Where as with the RPi and SPi you are kind of locked into one platform.
Given a little extra cash I wouldn't mind playing with and RPi 7c80 or 7c81 setup.

I've got a Atomic Pi sitting on a shelf that although I've installed Linuxcnc uspace on with an RT kernel I haven't had a chance to test with my setup.

Makes a lot of sense.
If I stick to a standard itx, any particular advantage to a Mesa via pcie (maybe I could use a riser and manage to fit the Mesa in a super compact itx case).

Other question: in case I wanted to upgrade to linear encoders with Mesa, do I have to worry about the interface? I don't know enough about the internals to understand if the encoder feedback is going to be handled by the fpga or if there is going to be a round-trip to the linuxcnc thread.

Honestly if the MB goes belly up Ethernet just needs a cable unplugged from the old and plugged into the new, no PCI or PCIe card to worry about.
I have a second LAN card in my 1u rack case, connected via riser, but I only put that in for hooking up to my local LAN.

I'm not up on encoders and such so maybe one of the gurus will chime in.