motion dynamics even if encoder position is the same, turret position may vary, depending on :
... backlash
... approach direction & speed
... approach type ( rapid or feed )
... slide resistance, depending on wear, heat, lube
... controller motion consistency / repetability, etc
* maybe other factors, like plastic/elastic behaviour
of course, it is considered that tool and fixture, are both rigid
when machine stops, inertia changes, movement chain is broken ... just saying, i don't know your casewhat happens when the machine rests for a minute?
also, pls be aware : even if you measure repetability, that value does not represent the machine when is cutting; under load, things are different
if you wish to increase precision, please share the drawing, the tool ( insert & holder, so to check overhang ), and i will draw you a higher precision toolpath and i will share few tricks, so to be able to increase precision class on older models / kindly