STL assumes 0.2mm layer height and 0.4mm nozzle and a ≤0.41mm first layer extrusion width.
Printing: Disable elephant foot compensation. Makes sure that first layer extrusion width is set to less than or equal to the extrusion width in the design. Currently the design uses 0.42mm, so the slicer needs to be set for max 0.41mm first layer extrusion width.
Parameterized Fusion design is at https://grabcad.com/library/ubl-15x15-calibrator-grid-1
The author remixed this model.