QymCAD is a free, open-source parametric 3D CAD application for mechanical design, product development, and manufacturing. It uses the OpenCASCADE boundary representation kernel to create precise solid geometry rather than polygonal approximations. Users can construct sketches with geometric constraints, mathematical dimensions, and associative references. Its modeling tools support extrusion, revolution, lofting, sweeping, fillets, chamfers, holes, and patterns. Parts can be combined into assemblies using configurable joints, movement limits, and interference checks. Parametric history automatically rebuilds dependent geometry when dimensions or earlier operations change. The application supports STEP, STL, DXF, and SVG import and export. Available for Windows, macOS, and Linux, QymCAD stores projects locally without requiring cloud services.
Features
- Parametric 2D sketching with geometric constraints and mathematical dimension expressions
- Precision 3D solid modeling powered by the OpenCASCADE boundary representation kernel
- Advanced modeling operations including extrusion, lofting, fillets, shells, and patterns
- Mechanical assembly construction with configurable joints and interference detection
- Associative modeling history with automatic rebuilding of dependent parts and assemblies
- STEP, STL, DXF, and SVG file exchange for CAD interoperability and manufacturing