Calibration Cube Z-Height  

Calibration Cube Z-Height

Hello All,

After some searching online and on this forum i can't seem to find a topic related to this issue. Here it goes:

When i print a Calibration Cube https://www.thingiverse.com/thing:1278865 the Z height doesn't seem accurate compared to the X and Y.

Printed in PLA, 0.2 layerheigt, 20% infill, 45mm/s. Extruder 210C, Bed 60C

X Meassure's 20mm dead on
Y messures's 20mm dead on.
Z measurres 20.2mm

1. Did Z Calibration
2. I started with checking Live Z adjust on my first layer, i ran the "Z Adjust my way" and got it nice smooth surface. Seems good.
3. I checked forum's and found out i need to calibrate Extruder; Measure software distance G1 E100 F100 vs filament distance. Got it dead on again
after some adjustments.
4. Lastly i printed the extrusion multipier Calibration Cube (40x40x40) to measure the average wall thickness, it was a little off. However i measured the
Z height of the Cube and it was 40mm dead on, X 40mm, and Y 40mm..

the Miltiplier Calibration cube however is a Prusa generated Gcode file. The XYZ Calibration Cube's i sliced myself with Slic3r. I got a feeling it has to do with the Slicing or the fact the XYZ-Calibration cube has a thicker layerthickness then 1 and thus has something to do with the Z-Height.

How can i get my calibration Cube Z height to 20mm? The Extrusion multipier cube is however only 1 layer thick. does this have something to do with the accuracy?

Thanks in advance.