what do you guys think of this .I would like to get it right the 1st time if possable bridgeport Moog 4=1 reduction on ballscrew on table servo motor now the problem encoders !! us digital differential type . what resolution ? and can I mount them on the screw rather than on the back of the motor ? greetings to all from downunder

Any backlash, no matter how small between the screw and the motor will cause problems, if the encoders are placed on the screw. It will have a bad vibrating effect, while the motors continually seacrh for the correct position.