I have a simple linear translation stage that is driven by a screw, and I would like to attach a stepper motor to the screw drive. The axis of the screw and the axis of the motor are approximately colinear. The issue is that, as the screw turns it recedes away from (or advances towards) the motor. The spacing between the motor shaft and the screw drive can change by as much as 10 mm. A diagram of the problem and an example of the type of stage are shown below.
How can I couple the stepper motor to the screw drive in a way that allows for this expansion/contraction of the space between the two?