StepUp has two main functions:
- footprint aligner
- kicad_pcb to STEP converter
The first one will load the footprint library file (kicad_mod) and in case of wrong scale (not 1,1,1) or not allowed offset (not 0,0,0) or not allowed rotation (not 0,0,z) the tools will warn the user to reset those not allowed/suggested values…
NB the tools don’t change in any way the footprint library file nor the pcbnew board file… this has to be done manually by the user.
The second feature is the Kicad board to STEP converter… this feature will warn the user in case of wrong scale (not 1,1,1) but will manage all the other offset and rotation data… so if the user don’t update these footprint data inside the footprint and inside the board, the 3D model will result dis-aligned, compared to the alignment done in FreeCAD.
All the new library models are defined with the settings that StepUp is suggesting, but old ones may have different values.
StepUp board importer (STEP exporter) is taking in care of all offset and rotation values, to be able to manage whatever board is going to play with…
Moreover it is useful in some case to add inside the board some rotation or offset to the 3D models…
for example in case of a M3 spacer, you may want to have it on both side of the mounting hole… then your top spacer would have all values to standard values (0), but the one on the opposite side will have i.e. rot y angle = 180°, z offset = -1.6mm (board thickness)
Then you don’t need to have two different 3D models to manage mechanical assemblies