@mjpelletier raised some concerns about the reliability of the ground connection on the y bed plate. Currently the ring terminals are being held in place by a printed part. Due to variance in printed parts, there may be issues with getting good electrical contact.
The proposed fix:
fasten lugs to plate with stainless screw/lock washer then attach bracket over the lugs.
This will require a change to the printed part as well as some additional hardware to make work
This change should make installing the ground lugs to the plate easier as it will be easier to line them up
FWIW all 20 machines built with the current set up do not have grounding issues.