We measured the SF Stepper motor physical position (height) [mm] in terms of number of steps.

The result is -51412 [steps/mm]. It can be seen in the first figure. (sr2sfstepper20180306)

And we measured the usable range og the SF Keystone with the SF Stepper motor. This is by how much the keystone can be moved in terms of number of steps given to the SF Stepper motor. We present the raw data of this measurement and the usable range with the approximate curve.