Demoldability analysis
A moldability heatmap and pull-direction search help identify undercuts and trapped geometry before printing.
Browser-based mold generator for 3D printing
Turn any STL into a 3D-printable mold.
Cavity analyzes your model, finds a demoldable split and generates rigid or silicone mold pieces with the practical details needed for casting. The geometry engine runs locally in your browser.
- STL input
- Rigid or silicone molds
- Client-side geometry
- STL export
How Cavity works
From 3D model to printable mold pieces.
- 01
Upload and inspect the STL
Cavity repairs common mesh issues, analyzes wall geometry and prepares the model for reliable boolean operations.
- 02
Choose the mold workflow
Generate a rigid multi-piece mold or a flexible silicone mold with a printed supporting shell.
- 03
Calculate a demoldable split
The engine evaluates orientation, pull direction, undercuts and piece count before building the mold.
- 04
Add details and export
Configure joints, fasteners, sprues, vents and handles, then export the pieces as standard STL files.
Built for real casting workflows
The mold details are generated with the geometry.
Rigid and silicone molds
Use split rigid blocks for straightforward parts or a flexible silicone cavity with a printed jacket for deeper undercuts.
Casting channels
Add a sprue and configurable vents to give material and displaced air a clear path through the assembled mold.
Local geometry processing
The TypeScript and WebAssembly geometry engine runs in the browser, so the uploaded STL is not sent away for processing.
Frequently asked questions
What to know before generating a mold.
What is Cavity?
Cavity is a browser-based mold generator that turns an STL model into 3D-printable mold pieces. It analyzes demoldability, builds the cavity, adds practical mold features and exports standard STL files.
Do I need CAD experience to make a mold?
No. Cavity exposes mold parameters in a guided interface and calculates the geometry in the browser. You can still control the parting strategy, piece count, clearances and casting features when needed.
Can Cavity make molds for models with undercuts?
Cavity searches for pull directions and multi-piece splits that improve demoldability. For geometry that cannot release from a rigid mold, it can generate a flexible silicone workflow with a printed supporting shell.
Does Cavity upload my STL?
The geometry engine runs locally in your browser using WebAssembly. Your model is processed on your device; only account and support features require network requests.
What file format does Cavity export?
Cavity exports the generated mold pieces as individual binary STL files in a ZIP package, ready to import into standard 3D-printing slicers.
No desktop CAD installation required