Hi,
I think you are mistaken.
Irrespective of the units you have selected and more importantly what Mach4 regards as the units if you have set you x axis motor to 10,000
then if you issue a MDI command move one unit to the right then Mach and your controller will issue 10,000 pluses.
Your motor will turn and the axis mechanicals will move the axis. It may be that it moves a few mm or maybe a few hundred mm. Of course ideally
given that you are wanting to use mm units then you hope that it will move 1mm. If however your motor tuning is wildly out it may mean that it
moves 25mm, ie close to an inch. This would mistakenly lead you to believe that the machine is in inches not mm.
We need to confirm your tuning settings.
I understand you are using regular two phase steppers?
What have you set for the microstepping regime on your stepper drives?
What pitch is your ballscrew?
What, if any, is the gear/belt reduction between the stepper and the ballscrew?
Craig