LinuxCNC - considering an upgrade

I’m considering upgrading my x50 Woodworker (32x32) to a new controller. Leaning toward LinuxCNC - as an IT guy linux doesn’t scare me at all, and I have plenty of spare PCs. I’m not sure how to flesh out the configuration - hoping for some ideas here!

This is just a hobbyist machine - I don’t mind tinkering, but I want rock-solid behavior. I’ve lost steps and had glitches that I can’t explain away as EMI. I also want a reliable pause/resume for longer runs. Faster is always better - but not a priority. I also have a 2.2kW Spindle.

The Mesa 7176E controller seems obvious, and some sort of Geko for drivers. I want to add a rotary to the system, so I need 5 drivers. I’d like to switch to closed-loop steppers - but I’m having difficulty identifying the best option here. I am looking for ideas on what would be a good combination of equipment.

I’ve gotten tired of waiting for the Masso upgrade option - and I am starting to get the feeling that it will be expensive for what it provides (even though price is not a big motivator). I’m not convinced that the Masso controller is better than what a LinuxCNC/Mesa combination would provide.

Any ideas on what I might be missing? Has anyone gone down this path that would like to share what they put together?

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I ran the OF with LinuxCNC using the Mesa 7i96s card and a Gecko G540 for the driver on 4 axis with no rotary. At the time for the 7i96s card you had to be running on LinuxCNC 2.9 to support it which is/was considered development and may be unstable - they have since added support into 2.8.4 for the 7i96s which is the stable release train. As I understand it 2.9 is days away from becoming the new stable release train for LinuxCNC. the 7i76E card is an awesome one if you can get it, I ended up with the 7i96s because everything else was unobtanium at the time.

Since it 2.9 did not have deb packages to install you had to build from source, this was somewhat problematic but I managed to get through it after a couple tries. Then once you get past the tuning of PC (disable HT, virtualization, C-states and so on), kernel (isolcpus) and servo thread I was able to get a stable running platform that gave me features I did not have in the OF BB controller and the OF became a much more capable machine for me (mainly auto squaring and tool setter). Unfortunately other users of my OF machine did not find any of the available user interfaces to their liking and/or user friendly so I had to abandon it and ended up going Masso. I moved the LinuxCNC setup to the plasma table which only I use so the interface isn’t an issue.

The one lingering sore spot I have is on Debian 12 there’s an issue with the Realtek network driver and the realtime kernel on the fanless PCs I can get from work so latency is higher than it should be, in the 0.150 - 0.200ms time range which means the servo thread has to be set higher than 1000000 + network latency + jitter otherwise you will get read/write timeouts and other such errors. If you have Realtek NIC I’d stick with Debian 11.

One word of caution with some of the Gecko drivers, they’re not differential mode and if you ever go to the Masso you’ll need the differential receiver module to use them. I ended up getting DM542T drivers instead of the Masso differential receiver card when I went to Masso mostly because I didn’t know I needed it and it was like 3 weeks + $100 in shipping to get it.

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