Work out what kind of resolution you want your machine to have.
For instance if you want it at 1000th of a mm.....(I use metric)
So that's 0.001, so 1000 microsteps is 1mm,
so 1000 is your rev per unit,
if it's 5mm pitch screws then multiply that 1000 by 5,
driver steps per rev is 5000.
This would then need at least 42khz to be able to reach 5000mm/min rapids.


P.S. I hope you are one of the lucky few that gets a MVEM working. There are a lot of bad experiences out there.