Since I fully gutted the cabinet and removed all inside wiring (but not wires coming from the outside to the huge terminal block), I was able to test more stuff.
I did test the X-Y servo motors last night by just applying voltage to their DC leads. They moved nicely. At 30 volts incoming, the X-Y table moved at about 1 inch per second, and the motors consumed appx. 1.3 amps.
What this tells me is that the mill is not "broken" (no surprise here), and also that 80 volts and 20 amps total capacity of my power supply, should be plenty for my light home use hobby purposes.
What I will do, for now, is just make a convenient terminal block on the outside of the mill, so that I could move X,Y,Z by applying DC voltage to these terminals.
I will hopefully get to that tonight. Also tonight, I will start making aluminum adapter plates for the US digital encoders.
The next step would be to connect encoders to Jon's motion controller, apply voltage to DC motors and see encoder data displayed on the PC.
I will try to spend a long time without hooking up servo drives, to wire and program as much as possible of safety related stuff (limits, estop etc). My own hands will be motor controllers, so to speak.
With the encoders working, and hand motor control, this will be actually a fully working semi-manual mill!
i