Hi,
just enter the correct 'steps per unit' value in the Z axis tuning page. You will have to experiment to find the correct max velocity and accel.
Good place to start is the speed of the axis if the stepper is doing 500 rpm. Thus if the axis has a 5mm pitch ballscrew then the max velocity
would be in the region 500 X 5 =2500 mm/min. Common to start with accel of 10% of the max velocity, so accel=250.
Craig