I’ve been trying to create a mesh for a model but I can’t seem to make it work.
The thing that I don’t understand is that, after messing with parameters with some time, I could get it to fail on “only” 3 surfaces, however these surfaces are exaclty symmetric on the other side of the design as far I can tell, but the failure is shown only for one of the two “symmetric sets”.
I also tried halving the part to the use symmetry, but then the mesh logs failure on different surfaces.
I tried messing with tetreahedral mesh but it didn’t help.
If I lower the min element size, I get more faces with errors

I’m posting a pic of a top view of the piece, a detail of the surfaces that cause the mesh to fail and the parameters I’m using

Any pointer or reccomandation on what to try next will be appreciated.
Anything but simplifying the part design, that’s an option (for silly reasons I rather not get into) only if I can prove beyond any doubt that the current design is not meshable, which I don’t feel I can

This part is way too complex to obtain a good mesh of reasonable size. Of course, the mesh has to be tetrahedral and possibly generated with Netgen (Gmsh may struggle with this). You can play with element size settings and number of elements per edge/curvature but it will be really hard to mesh it properly. The nasty small faces and edges would essentially require tricks like virtual topology (ignoring some of them) but this is not possible with meshers in PrePoMax. Removing the small problematic geometric features (defeaturing) seems to be the only right way here. It would be justified by good practices in FEA (I doubt all those fillets are absolutely necessary for accurate results if they don’t lie in regions with important stress concentrations).

You can try the Geometry → Analyze tool to get information about the smallest edge size on your model. The setting for the smallest element must be equal to or at most twice the size of the smallest element.

Some faces might have “bad” geometrical descriptions, so the mesh fails. You can try merging the failed faces in CAD or remodeling the faces where it fails.

I would suggest to try it with Gmsh: Additional to “Meshing parameters” use “Tetrahedral Gmsh”, here deactivate “Transfinite faces” and change the 2D meshing algorithm to “Automatic”, select 1st order optimization “Netgen” and 2nd order optimization “High order elastic”. If this doesn’t work, try “High order” for 2nd order optimization. I guess this should also work with a relative coarse mesh and projected midside nodes on geometry.