To explain the above in more detail I have created a sample project and have attached it to this message:
Multi.zip (174.6 KB)
The project consists of two PCBs that I have put into one folder (normally one should not do this), but for the sake of sharing the fp-library it should be ok.
There is no schematics in this project to keep things simple. In my other designs I created a “function- block-like”-symbol that represents the tabs where the other PCB will be inserted and soldered to the main PCB.
The main board is standard DS 1,6mm and the daughter board (PCB-A) is SS-AL 1,0mm.
In the FP-library are two footprints:
- Main-EdgePad-2pos is the footprint that is placed on the main PCB consisting of two pads and one oval hole that accepts the daughter PCB. The 3D-Model attached is the STEP/VRML Export of the complete daughter board.
- PCB-A-EdgePad-2pos is the footprint that is placed on the daughter board. The 3D model attached are the two solder points that connect the two boards. They have been created with FreeCad using Kicad StepUp. The FCStd is also attached in 3d-models.
When using the 3D-viewer on the main board you can see both boards how they are assembled together. There is even the solder joints visible that keep the two boards together.
The main board is renderd in detail, with silkscreen, copper, … visible. The daughter board is rendered using the STEP export of the board. It’s mechanical representation is correct, but it is missing the nice colors (Aluminium core) and decoration (silkscreen, tracks, …).
This is great for working with complex assemblies. The daughter board can even stand at an angle to the main board. Since the placement is defined in the FP-editor the daughter board can be edited and the results are updated by exporting the 3D and updating the footprint in the main board, which is fast. And all is within KiCad. Updates on the main board are updated immediately.
The only thing that bothers me is that the FP-editor does not accept the *.WRL export of the daughter board that has been generated by PCBnew.
I can import this file successfully in FreeCad and it shows all the desired details.
But when I try to open it in the FP-editor and assign it to a footprint it does not render it.
For the daughter board rendered as step this works perfectly.
It would be great to be able to also import the daughter board as VRML, but the internal structure of a single component generated by FreeCad’s KiCad StepUp plugin looks totally different from the VRML export of PCBnew.
In the first graphical shapes are defined inline, with corresponding appearance statements. In the VRML export from PCBnew elements from external files are linked and positioned in space.
It seems that the VRML importer does not understand all VRML commands.
Please let me know what you think about this. Please let me know about your Multi-Board-Design workflow.
