Testing Rostock Mini and noticed that axis only moves by 0.2mm steps. I'm using Pronterface 0.1mm manual move and stepper motor moves only every second click. The distance itself is correct as well as steps per mm.
There are 44.444 moves per 1 mm so the accuracy should be 0.0225 mm per one step.
Since pronterface sends an exact G-command to move 0.1mm, this must be Marlin issue.
Moving down generates followed actual coordinates (not DELTA!)
RECV: X:5.80Y:-1.50Z:61.90E:0.00 Count X: 225.38Y:230.51Z:226.82
RECV: X:5.80Y:-1.50Z:61.80E:0.00 Count X: 225.34Y:230.47Z:226.76
RECV: X:5.80Y:-1.50Z:61.70E:0.00 Count X: 225.20Y:230.31Z:226.62
RECV: X:5.80Y:-1.50Z:61.60E:0.00 Count X: 225.16Y:230.27Z:226.55
RECV: X:5.80Y:-1.50Z:61.50E:0.00 Count X: 225.00Y:230.11Z:226.42
Calculation is not exact either since movement appears to happen in 0.13mm+0.07mm sequence (or 0.14+0.06)
Anyway I would like to have 5 steps every 0.1mm move, please :-)