Why did the handle for the lathe tool post break off?
Center drilled small holes on the ends of the arms.
Drill, debur, drill again and debur again. Repeat.
Center drilled, and drilled the servo arms shaft.
With the servo arms off the mill I can now: Use the mill to extract the broken end of the tool post handle; Back to the lathe turn and thread the new handle; Drilled the ends of the adapter to 0.5"; Then I discover that the tool post can't get close enough to the center line to bore the rotary table adapter; Back to the mill and the rotary table to use an end mill to expand the holes in the ends of the adapter to 0.552" and 0.559"; Then I can get back to shaping the servo arms.
That didn't work. I couldn't hold the adapter to mill out the ends. Back to the lathe and with the compound slide forced to a 45° angle I could just get a cutting tool in the ends of the adapter to bore the holds big enough to work. Turns out there is not a lot of extra space inside the adapter.
Rotary table mounted, with adapter, ready to mount jig #1 and continue shaping the servo arms.