My trouble with the hub and fillets seem to be consistent & it builds no errors looks solid in Rhino, selected the surface in the first shot it’s really twisted & took careful work to have it fillet in one pass no chaining.
With a single surface and hub I offset both at one time to 1.3mm & trim, then do a variable fillet, chamfer also works @ 0.35mm that looks fine no errors but isn’t solid, it’s a mesh in other tools.
So now I need quick ideas on what may work, the rest are edge fillets, deadline is tomorrow & thought I was OK hadn’t checked as STL for a while & saw black so checked in FreeCAD same thing.
It’s the basic fillet against the hub and goes in one piece that isn’t solid, haven’t tried every combo of settings so could use advice there, my thought is I’m missing a step if not the wrong settings.
… in MeshLab: