Great machine and very informational build. I will implement some of your ideas on my next build, especially the system for oiling the bearings.

I am slightly curious about the ceramic bearing spindle. From my understanding, if you / god helps no to happen/ hit the spindle by accident on the table or a part, what would happen to the ceramic balls? You say there is an electric contact. Maybe only the lower pair is ceramic?

From where did you get that encoder for the spindle? Does your VFD support encoders?