Re: Ball screw number step
I'm not certain that I understand your question.
The ball screw will have a specific pitch, for example 10 turns per inch (which means that one complete revolution of the screw will advance the nut by one tenth of an inch), or perhaps a metric rating such as 5mm advance per turn.
Typical stepper motors will have 200 steps per revolution (when the single-step mode is used). If the driver is set up for half-stepping, then it will take 400 steps to do a single revolution. Similarly, with one quarter microstepping, it will take 800 steps per revolution.
So, based on the stepper motor steps per revolution and the ball screw's pitch, you can figure out the linear travel of the ball screw nut for one step of the motor.