An AI 3D model generator for parts that have to fit
Most AI 3D generators turn a prompt into a sculpted mesh: fine for a dragon figurine, useless for a clip that has to snap onto a 22 mm tube. FitPrint is an AI 3D model generator built for functional 3D printing. You describe the part, it asks for the dimensions that matter, writes parametric CAD code (OpenSCAD), renders it in your browser, measures the result and only then gives you an STL.
Because the model is real CAD, every dimension is exact and editable with a slider — no regenerating and hoping.
- Output
- STL + parametric OpenSCAD source
- Accuracy
- Exact millimetres, rendered and measured before download
- Tolerances
- Calibrated to your printer (fit gap test print)
- Best for
- Knobs, clips, brackets, mounts, adapters, boxes, holders
- Price
- First part free, then 7.99 €/month or 59 €/year
How the generator works
- 01Describe the part in plain language (any language) and optionally add a photo.
- 02FitPrint asks only for fit-critical measurements and tells you where to put the calipers. For commercial products (phones, controllers, standard parts) it looks the dimensions up on the web.
- 03The AI writes an engineering plan, then parametric OpenSCAD code, including the real objects the part works with (the phone, the screw, the wall).
- 04Your browser renders the model, measures its bounding box, checks that the real objects fit, can be inserted and are held, and lets the AI fix anything that fails.
- 05You tweak dimensions with sliders and download a print-ready STL plus the .scad source.
Mesh generators vs. parametric generators
| Text-to-3D mesh generators | FitPrint (parametric CAD) | |
|---|---|---|
| Geometry | Sculpted triangle mesh | CAD code with exact dimensions |
| Holes & shafts | Approximate | Exact, with clearance for your printer |
| Editing | Regenerate the whole model | Sliders for every dimension |
| Checks | None | Bounding box, fit, insertion path, floating pieces |
| Best use | Figurines, art, organic shapes | Replacement parts, mounts, holders, adapters |
Try a prompt
Frequently asked questions
Can an AI generate 3D models that are ready to print?
Yes, if it generates CAD instead of meshes. FitPrint writes OpenSCAD code, renders it, checks dimensions and printability, and exports an STL you can slice directly in PrusaSlicer, Bambu Studio, OrcaSlicer or Cura.
Is the STL watertight?
Yes. OpenSCAD produces closed, manifold solids, and FitPrint additionally flags parts that accidentally consist of several floating pieces.
What can't it do well?
Very organic shapes (faces, animals), textures and complex multi-part mechanisms are still hard. For those, a mesh generator or a human CAD designer is the better choice.
Which AI model does FitPrint use?
FitPrint uses a Claude model from Anthropic to plan and write the CAD code; rendering and all measurements happen locally in your browser with OpenSCAD.
Related
Updated · Generated parts are a starting point — always test-fit before relying on a part.