Geometry Error Checker
Broken CAD File? Diagnose It in Seconds
CAD geometry errors — open shells, knife edges, and invalid topology — are a leading cause of CAM toolpath failures and vendor file rejections. Detect them in STEP, IGES, and STL files before manufacturing, not after.
Upload CAD FileGeometry Errors Odin Detects
Most geometry errors are invisible in the CAD viewport but cause downstream failures in CAM, mesh generation, and manufacturing. The errors below are the most common reasons vendors reject STEP files and CAM runs abort.
Open Shells (non-watertight)
An open shell (non-watertight) is a connected surface or set of faces that does not form a closed volume. Gaps or missing faces leave the solid open.
Open shells (non-watertight) cause CAM failures, meshing issues, vendor rejection, and rework. Many CAM and mesh generators require closed, watertight geometry.
Why it fails:
- CAM boundary detection breaks
- Mesh generation fails
- Vendors reject non-watertight solids
Knife Edges
A knife edge is an edge formed by two faces meeting at zero or near-zero thickness. The geometry has no measurable material width along that edge.
CAM and meshers choke on knife edges: unstable toolpaths, meshing artifacts, and non-manufacturable geometry. Detecting them in STEP and IGES before CAM or 3D printing avoids failed runs and rework.
Why it fails:
- Unstable toolpaths
- Meshing artifacts
- Non-manufacturable geometry
Wall Thickness
Coming soonDetect thin walls and risky thickness transitions that lead to sink marks, weak parts, and failed manufacturing.
What it catches:
- Variable draft thinning (tapered walls)
- Boss proximity thinning (inter-feature distance)
- False-positive near-miss tolerance cases
Sharp Edges
Coming soonFlag sharp edge conditions that violate safety thresholds or create finishing and handling risks.
What it catches:
- 90° exterior corner safety threshold
- Sharp junctions between curved surfaces
- Tolerance near-miss angles (false positives)
Ready to check your CAD?
Upload your file and get instant geometry diagnostics. Free for individuals — contact us for team and enterprise access.
Frequently Asked Questions
- What is an open shell in a CAD file?
- An open shell (also called a non-watertight solid) is a connected surface or set of faces that does not form a closed volume. Gaps or missing faces leave the geometry open. Most CAM systems and mesh generators require closed, watertight solids — an open shell causes toolpath failures, mesh errors, and vendor rejections.
- What is a knife edge in CAD?
- A knife edge is an edge where two faces meet at zero or near-zero material thickness. The geometry has no measurable width along that edge, making it non-manufacturable. Knife edges cause unstable CNC toolpaths, meshing artifacts in FEA, and failures in 3D printing.
- Why does my vendor reject my STEP file?
- Vendors most commonly reject STEP files due to open shells (non-watertight geometry), knife edges, or invalid solid topology. Running a geometry check before sending the file catches these issues before they cause delays or back-and-forth.
- What file formats does Odin support?
- Odin supports STEP (.step, .stp), IGES (.iges, .igs), and STL (.stl) files for geometry error detection.
- What causes CAM toolpaths to fail on a geometry error?
- CAM systems rely on closed, watertight geometry to compute tool boundaries and offsets. Open shells break boundary detection algorithms. Knife edges create degenerate geometry that CAM cannot safely traverse. Both cause toolpath generation to fail or produce incorrect, unsafe results.
- How do I fix an open shell in CAD?
- Identify the missing or misaligned faces using a geometry checker, then close the gaps by stitching surfaces, filling holes, or healing the solid in your CAD tool (e.g., Heal in CATIA, Knit Surface in SolidWorks, Stitch in Fusion 360). Odin highlights the exact location of the open shell to guide the repair.