Non-manifold issues, don't know what to do next - any ideas?

Hello all,

(New user of blender here, this model is very messy no doubt)

I’ve spent a month or so on learning the basics of blender, making this model (some of which is original, and some of which I took from other free open source models online, I hope that’s okay) in order to 3d print it. Now that I have my model looking like I want it, I would like to send the file to shapeways as an .STL in order to have it printed, but there’s a lot of issues with non-manifold edges.

I’ve tried simulating the model as a fluid, using shrinkwrap, generating a solid in meshmixer, with no luck. Either the model loses 50% of the detail, or the simulation/modifier can’t approach the level of detail I’m looking for.

I basically just want this model as a printable STL file - some loss of detail is perfectly fine.

Any ideas or strategies that people might have?

I’ve attached the file if people want to look at it. Thanks in advance for any suggestions.


printingpre2.blend (13.5 MB)

Yes, it’s a big mess. Not sure there is an automatic tool to fix a model like that with all the interior faces and self-intersections that makes the model completely nonsensical.

  • Object scale is unapplied. Ctrl+A -> scale to apply.
  • Apart from 4 small unconnected pieces, the model consist of connected geometry that define many surfaces in a way that the program doesn’t know which one it should follow (interior faces). As one connected geometry, it should define one closed surface where all vertices are part of that surface, all connected with edges, and each edge connected to two faces. If the model is hollow, it would use two of such surfaces, outer and inner, which wouldn’t be connected to each other in any way

The model pieces aren’t merged correctly. If you have all the pieces, could try first making all the pieces manifold and then there’s a chance to start merging them with boolean union. If the receiving application can interpret intersecting geometry (like Slic3r can), could intersect those manifold pieces clearly with each other and the program would count them as one solid.

If those aren’t an option, the only sensible option left to fix the thing in Blender might be to do a retopology pass on it. Meaning, using a new object and build a new surface on top the existing one, snapping to the existing form underneath. Search for “blender retopology” to find tutorials if needed. Could make separate objects of some of them and have a successful boolean union later, if that helps the workflow.

Top and bottom, from left:

  • Manifold geometry, separate objects, two surfaces, solid
  • Manifold geometry, one object with two unconnected meshes, two surfaces, solid
  • Manifold geometry, one object, one surface, solid
  • Manifold geometry, one object, two surfaces, hollow

I tried repairing this in Netfabb, there are just too many issues to do it quickly.

It is possible CADspan might work on this but it has a tendency to “melt” small detail. There is a free trial available.