[strantor]

LinuxCNC can run both open loop (with dumb or smart drives), or closed loop back to LinuxCNC with scales. Yes, it have following error scope features if you have load encoders.

All of the CNC control software mentioned above will work. LinuxCNC is by far the most powerful of the the bunch, but it can be the most intimidating and fiddly.

There are some folks on LinuxCNC forum playing around with EtherCat master plugins and I believe there are a number of working systems out in the wild... but like all things LinuxCNC there's no vendor you can call if things go wrong. Support, while excellent on-line, is limited to asking questions on the forums.

For your use case, UCCNC will not be appropriate. I use it & like it on my mill and three plasma systems, but it has no lathe-specific functions or screenset available. It can, of course, do spindle synchronization, but there's no tool X-offsets or any of the other 'ready-to-run' lathe functions you would expect on a lathe control.

I think your best bet is to install LinuxCNC (free) and play around with it. Your machine will be oddball enough that you'll probably want a controller with enough customization that you can set it up so it makes sense with your vertical thing.

Centroid is probably the most polished interface, but you're locked-in to their system. Upgrades are expensive, and it's not really customizable unless you go with the top-tier Oak controller.

LinuxCNC with an ethernet Mesa card is probably your best bet. Once you get it sorted out with your machine it'll be cut and paste if you build others.

I am (or was) pretty familiar with LinuxCNC and Mesa as that's what I used on my mill, and it wasn't exactly a simple retrofit. I had the trial by fire treatment. I do like it and think it's very powerful, and the forums-only tech support wouldn't be a big deal except that it seems answers that were correct 5 years ago are no longer correct. I like to search and try to figure things out before running to the forum to ask, but it seems with LinuxCNC it's best to just ask. I've wasted more time trying to force obsolete solutions on my time-now problems than I would have spent just creating a new thread. But on the flip side, there are a whole lot more people available to help than there are in the support dept of a typical vendor.

I've become a half decent Python programmer (learned from non-CNC projects) in the time since I did my mill retrofit, so this should all come a lot easier this time around if I go with LinuxCNC again. I think that's what I'll do. But instead of the analog velocity Mesa board with encoder feedback I'll get something else. I'll go on the Mesa site later and start researching what's needed, but if anyone already has a clue, clues are appreciated.