I want to build a horizontal spindle , heavy duty, metal cutting cnc mill. It will have a number 50 taper spindle. For the y axis (up and down) The linear guide rails will be relatively short, so I want to use 3 or 4 ball screws,each with it's own servo motor, using the master-slave feature.
Will this work? What happens during homing and zero return at power up,etc. The ball screws must remain in sync at all times or there will be tremendous racking forces created on the guides. I suppose I could put a swivel connection in there, but that would reduce stiffness.
Do the ball screws need to have the same pitch? I have read about a feature called electronic gearing, would this work to compensate?
I have thought about using one big servo motor with timing belts connecting to the four ball screws. The timing belt pulley center distances would be about 24 inches. I wonder if the strech and "flapping" with a belt that long would introduce too much error.