Extrusion Multiplier Calibration and actual dimensions of printed parts
I did the extrusion multiplier calibration for my MINI now several times, always using the "precise method". I get now very close to the 450µm thickness - with some systematic deviations on the fours sides of the cube. I thought so far so good... I tested also if the weight of the part that is as specified by Slicer is the same as the actual weight and that is the case. So I thought that I have a proper extrusion going on.
However, when I print parts now, the overall dimensions do not fit and the parts are usually slightly too large. When I print again with 100% flow, everything fits and the dimensions are correct - but I can see signs of underextrusion in the first/top layers.
Was I doing something wrong for the calibration? I measured with a proper micrometer and on multiple places on each surface. I even printed on different positions of the bed... How can it be, that a single wall is "exact" while the overall part then gets too large?Do I miss some setting in slicer to compensate for something?
RE: Extrusion Multiplier Calibration and actual dimensions of printed parts
This post is a copy of a post by reox. This one has a link in it.
RE: Extrusion Multiplier Calibration and actual dimensions of printed parts
FDM printing will shrink a small amount. In the Prusa Slicer there is a compensation variable you can change to take this shrinking into account.
I print a 40mmX40mm cube and enter the compensation values. Then print again and test. I have printed 200mm test pieces and less than 0.1mm error.
You will have to enable the "Normal mode" to change this. Then the setting is under Filament > Advanced.