What we tested
| File | Bambu Studio said | Actual problem | Result |
|---|---|---|---|
| Thingi10K 116287 by dutchmogul (CC BY-SA) | Error: 1 non-manifold edge | 11 non-manifold edges, 12 zero-area faces; FixSTL rebuilt 34 faces into a verified solid | Same filament before and after repair (667.86 mm) |
| Thingi10K 60268 by Geir (CC BY) | Error: 1 non-manifold edge | Flipped faces, 5 non-manifold edges; FixSTL repaired it to a verified solid | Same filament before and after repair (903.75 mm) |
| Thingi10K 63405 by destroyer2012 (CC BY-SA) | Error: 1 non-manifold edge | 5 open and 5 non-manifold edges, 16 self-intersections; FixSTL rebuilt 57 faces into a verified solid | Filament 1790.36 mm before, 1790.35 mm after repair |
| Thingi10K 138197 by MakerBot (CC BY-SA) | Error: 1487 non-manifold edges | 3,904 duplicate faces and 6,306 self-intersections; FixSTL removed the duplicates, 50 intersections remain | Same filament before and after repair (3195.85 mm) |
| Thingi10K 61459 by pmoews (CC BY) | Error: 1 non-manifold edge | Two overlapping parts (18 self-intersections); FixSTL repaired the edge, the overlap remains | Same filament before and after repair (7175.61 mm) |
| Two 20 mm cubes touching along one edge | No warning | 1 non-manifold edge; FixSTL leaves it unchanged | Sliced as two cubes joined along a line |
What is going on
Bambu Studio counts an edge as non-manifold when three or more triangles share it, measured after the repair it runs on every STL it loads (source). That repair pulls simple cases apart first: two cubes touching along one edge showed no error at all in our test, and two merged cubes with a wall left between them showed "Info: 4 open edges" instead.
In this version the non-manifold vertex count is never filled in, so the longer variant "Error: N non-manifold edges, M non-manifold vertices" does not appear.
FixSTL repaired 12 of the 60 files to a verified solid. The others were only partly repaired, mostly because parts overlap or the damage is too large to rebuild locally; the full results are on How we test.
What was actually wrong
How to fix it
- Check the file in FixSTL. It lists the non-manifold edges together with the duplicate faces, self-intersections and overlapping parts that usually come with them.
- Apply the repair. Duplicate faces, unwelded seams, thin flaps and small damaged patches are fixed; overlapping parts are left as they are.
- If parts overlap, join them with a boolean union in your modelling program and export again.
- Re-import into Bambu Studio and scrub the layer preview where the error was.
Source: Vendor source code · github.com · Bambu Studio 02.08.02.61 on macOS