[Newbie] Mach 3 Or 4??

[RonGinger]

You are doing it backward- you must first set your calibration- or the steps per unit of travel. This is not a tuning thing, it MUST be set to match the actual values of your motors and lead screws. Your motor is 200 steps per rev, you G540 is 10x microstepes, so it takes 2000 steps to turn one rotation of the motor- if this is connected directly to the leads screw then you multiply that by the number of turns to get one inch.

Then you can tune for the fastest safe speed and acceleration. Using reallylarge stepper motors will give you lower speeds- more rotor inertia makes them slower. This is a case where bigger is not always better.