Geometry Check Launches Free Fusion 360 Add-in for Flawed CAD Sketches
An open-source CAD inspection tool locates hairline gaps, near-square angles, and tiny segments.
1Automating Imperfect Sketch Detection
Geometry Check is an open-source, free add-in developed for Autodesk Fusion 360 to identify subtle modeling flaws. In complex CAD workflows, minute discrepancies such as 0.05 mm gaps or 0.3° angle misalignments often break downstream extrusion and offset operations, requiring time-consuming manual inspection to locate.
2Core Diagnostic Rule Engine
The tool launches with dedicated diagnostic checks covering common geometry failures. Check A8 identifies near-right angles within 0.5 degrees of square, while Check A9 flags hairline gaps preventing profile closure. Check A1 marks disconnected endpoints, and Check A5 identifies micro-segments that disrupt shelling and export features.
3Non-Destructive Scanning Defaults
Operating on a detect-only baseline by default, Geometry Check leaves native geometry untouched. The inspection tool scans sketches, explains each flagged anomaly in plain language, draws a red marker, and automatically centers the active camera view on the problematic vertex, excluding construction and projected elements from results.
4Self-Verifying Experimental Fixes
An optional setting introduces automated remediation through single-step undo operations. When enabled, the engine applies recommended geometric constraints and immediately re-evaluates the sketch. If the fix causes feature rebuild errors or introduces new defects, the tool automatically rolls back the change and displays the failure reason.
5Persistent Metadata Ignore Management
Intentional modeling variations, such as functional draft angles or open toolpaths, can be suppressed with an ignore action. Suppressions are recorded directly as metadata within the design file without modifying geometry. Users can unhide and restore ignored items at any time through the dedicated interface menu.
6Integration and Cross-Platform Verification
Installation requires placing the repository into Fusion's Scripts and Add-Ins folder, surfacing three inspection commands under the Design workspace. The software was developed and validated on macOS, while Windows support is currently in open alpha testing to evaluate platform-specific behaviors and identify edge-case calculation bugs.
7Automated Fixtures and Testing
The project includes a built-in test suite via run_fixtures.py, creating broken sketches alongside decoy entities directly inside Fusion. The automated pipeline executes against the central check registry to ensure every diagnostic rule and repair script behaves deterministically, avoiding false positives on clean sketch geometry.
8Privacy Model and Architectural Trajectory
Geometry Check operates under the MIT license without telemetry, tracking, or network dependencies. Future releases aim to expand beyond standard 2D sketches into duplicate curve detection, self-intersections, and complex 3D body topology diagnostics, streamlining collaborative design reviews and reducing manual troubleshooting overhead.