I want to make CNC mini 3 axis and use Arduino and Mach3 to control it, or mach3 control my CNC mini.
Ok I am not stopping you, go ahead and make it.
Was there a question?
You may find something useful in stepper motor basics
You need to know what sort of output is produced by Mach3. That is beyond the scope of this Forum.
...R
um... MACH can control the steppers directly.
what would you use the Arduino for ?