I have a Servo model 100 BP knee unit running the table X feed on my Millrite. It works fine, but I did have to swap the wires to the brushes to get the movement directions correct. Knees run backwards from the X and Y. I also needed to add a new direction label over the existing one. I also have a Servo model 90 unit originally for a BP X axis that I will be using on the Y axis of my Millrite. The differences are minor.
The Millrite has a 5/8" square shank to drive the knee. I made two adapters with .450" hex male to 1/2" square male (one for a friend, eeler1) and use a HF cheap 1/2" drill (less than $25 out the door with 25% coupon) and a 1/2" drive, 5/8" eight point socket to power the knee up and down, works well. I will post that in a separate thread for reference.