I am very new to this and have drawn a couple of wheels I wish to print the first 1 printed ok but the second will not print the centre boss these were drawn on sketchup the first was solid in sketchup but the large 1 which I am having trouble with was put through netfabb to repair it
I’m not to experience with sketchup, but I’m leaving towards the thought tat the hub in the larger wheel is not water tight, or the surface normals are flipped. When you created the hub in sketch up, did you make it interfere at all with the spokes? Out may help to, as this would ensure you don’t have any gaps. Again, I’m not experienced in that software, but have tons of CAD solid modeling experience, and when I used sketch up, it seamed like it was similar to using primitive solid in autocad.
Good luck
Sketchup is know to produce faulty stl files. As the repair routines in Slic3r and Netfabb often seem to produce similar repairs (including new faults, like misshaped geometry or covered holes), you might want to look into manually patching up the files up in Meshlab or Blender. Or use a different CAD tool in the first place, like FreeCAD.
@Thomas_Sanladerer The problem comes when your file is missing a face that is supposed to have a hole in it. The software sees that as two holes rather than one hole where a donut-shaped face is missing. The solution is to add one facet manually connecting the inner and outer edges (netfabb basic can do this, and any mesh editor that lets you directly manipulate vertices and faces should too), then use the automated repair. Since the hole is no longer a full loop, it the repair algorithm should interpret it properly.