UPDATE COMMING SOON
I did a complete control retrofit using only the original DC servo motors, encoders, cables and one small control cabinet.
Here is what I started with. 1984 Bridgeport R2E3.
Spindle drive is now ABB ACS350 controlled via PWM.
Servo drives VSD-XE
Following error on all 3 axis < 0.0004″. Accurate for this type of mill
New hardware based motion controller is from EdingCNC
Modern control works great on touch screen
The original variable speed system was removed and replaced with 2:1 & 1:2 ratio sheave & bushing arrangement giving max rpm 7000 @ 120Hz
Some of my first test cuts
More to come