Not much been happening lately. Ballnut carrier now has all the lathe work finished on it, and is now just needing the holes drilled in it for mounting the pulley, along with a slot for the locking tab washer for the securing nut.
I'm holding of setting up the rotary table just now, as I'd like to drill/thread/counterbore/sink all the required holes at the same time to make sure everything is going to line up.

I've just ordered the required 72t pulley from HPC, but they're not showing as having any in stock, so this project may be on hold for a short period until that appears.
However that does mean I can turn my attention back to the controller...