Reverse engineering in FreeCAD
Reverse-engineer parts in FreeCAD with AI.
Reverse engineering in FreeCAD with AI: Oscar for FreeCAD builds a part as native features with named dimensions. Open source, and free with a local model.
How to reverse-engineer a part in FreeCAD with Oscar
Oscar for FreeCAD is an open-source workbench for FreeCAD 1.1 or newer. It builds a part as native FreeCAD features and puts each dimension in one spreadsheet. For a 3D scan, Oscar in your browser rebuilds the part first. Then you open the model in FreeCAD.
- 01
Install Oscar for FreeCAD
Install Oscar from the FreeCAD Addon Manager, or download the ZIP file. You need FreeCAD 1.1 or newer.
- 02
Connect an AI model
Use a local model through Ollama or LM Studio, the API key of your AI provider, or your OriginShape account.
- 03
Give Oscar the evidence
Attach a photo, an image of the old drawing, or a DXF drawing. Or type the dimensions that you measured. For a 3D scan, rebuild the part in Oscar in your browser first.
- 04
Oscar builds native features
Oscar plans the part. Then it makes sketches, pads, pockets, holes, and fillets. Each dimension goes into one parameter spreadsheet.
- 05
Check and export
Oscar checks the model after each change. Change a cell in the spreadsheet, and the part changes with it. Export STEP, STL, 3MF, or BREP.
Worked example: a stepped shaft
- Input
- shaft_scan.stl · 8,000 points
- Datum
- One rotation axis
- Features
- Profile sketch · Revolve 1 · Taper 1
- Dimensions
- Ø24, Ø36, and Ø28 mm · 120 mm overall · 21.80° taper
- For review
- Shoulder position at z −35.00 mm: confirm
- Output
- shaft.step · a feature tree with named parameters
Three ways to connect an AI model
| Cost | Where your data goes | |
|---|---|---|
| A local model (Ollama or LM Studio) | Free of charge. You need no API key. | Your data stays on your computer. |
| Your AI provider | The price of your provider. You use no OriginShape credits. | Your data goes to your provider. |
| Your OriginShape account | OriginShape credits. You can start free. | Your data goes to OriginShape, and then to the AI model. |
Common questions
On the blog: Oscar for FreeCAD is out: free, open-source AI in FreeCAD
Is there an AI plugin for FreeCAD?
Yes. Oscar for FreeCAD is an open-source workbench for FreeCAD 1.1 or newer. You tell Oscar the part that you need. Oscar builds it as native FreeCAD features with a parameter spreadsheet.
Can I use AI in FreeCAD free of charge?
Yes. Oscar for FreeCAD is free under the Apache-2.0 license. With a local model through Ollama or LM Studio, you need no API key, and your data stays on your computer. Small local models work best on simple parts.
Can FreeCAD convert an STL file to a solid?
Yes, but the solid gets a face for each triangle of the mesh. You cannot change a diameter. Oscar rebuilds the part as features with named dimensions.
Can Oscar for FreeCAD rebuild a part from a 3D scan?
Oscar in your browser rebuilds a 3D scan as a feature tree. Then you open the model in FreeCAD. In FreeCAD, Oscar builds a part from a drawing or from your measurements. It can also import a mesh and measure its size.
Have a part without usable CAD?
Rebuild it with Oscar in your browser. If you do not have a scan, send us the part. We will plan the capture with you.