Doh... I did post a reply, but it seems it did not get saved :( In the meantime I tried more things, so here we go again:
chrisb wrote:You have redundant constraints in "Sketch" and "hammer part" which you have to delete.
This is weird, because those constraints were not there when I modelled the sketch and I did not edit the sketch afterwards. Does the mean the solver may produce different results when re-opening the sketch?
chrisb wrote:That will result in a problem which I couldn't track down with "not holes". Perhaps it is a topological naming issue, you might detach and reattach it from its support, if it doesn't help you might have to reconstruct it.
If I repair the sketches in FreeCAD 0.17 it is enough to make the fusion work.
I guess I could try to compile from git and see if it helps... after I repaired the sketches the part with the holes worked, but the part with the pins did not.
chrisb wrote:By the way: both halves seem to be almost mirrors. So you better model one half, mirror it and attach then the sketches for "holes" and "not holes".
Actually not almost - they are mirrors, it's just that one part has holes and the other part has pins. I tried the mirror function, but it did not really help me in regard to mesh conversion... I rearranged and reconstructed the objects several times and did not get anywhere so far :( So I guess I'll try to compile 0.17 and see if it helps, otherwise I really do not know what else to try...
Thank you for the hints!