prusa, i3 pro b, copy
i think, or calibration in general.
after printing beautifully an iPhone case, the phone doesn't fit.
so i printed some (3) 30x20x10 mm oblongs.
and my prints are all pretty much the same.
X, meant to be 30, is 29.52mm
Y, should be 20, and is 19.77mm
Z, should be 10, and is10.18mm
i know i can adjust the xsteps steps etc,
X and Y are 78.74
Z is 2560
but whats the system of tweaking? is there a formula, or do i blindly add 10 and see what prints?