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FreeCAD AI Modeling Guide

FreeCAD AI Modeling Guide

Say the dimensions, get the model. Redraw drawings, photos, STEP and STL as parametric models — then fix them, inspect them, and take them through drawings and analysis.
Build your first model in 5 minutesStart with the install

What this site is

Section titled “What this site is”

Attach cadxray to FreeCAD 1.1.3 and AI coding tools — Claude Code, Codex CLI, Gemini CLI — can read, build and fix the FreeCAD document you have open. This site is not documentation for that connector. It teaches you how to build 3D models by talking to it. Every page has «Say this» boxes: copy the sentence, paste it into your AI tool.

Install

FreeCAD 1.1.3, uv, git, an AI tool. Two terminal commands. If you get stuck, a diagnostic command tells you what went wrong. Start →

Connect an AI tool

How to register cadxray with Claude Code, Codex CLI and Gemini CLI, the rules file each one reads, and how the three differ. See →

What it can do

Build from scratch, build from drawings and photos, redraw STEP and STL, fix, inspect, 2D drawings, 3D printing, structural analysis. See →

Hands-on exercises

Ten of them, from four holes in a plate to an observation frame. Input files, the exact prompts, how to check, and what success looks like. Start →

Writing prompts

What to include so it works the first time, how to answer when the AI asks back, and good and bad examples. See →

Reference

All 36 tools, the limits, the vocabulary. Look things up when you need them. See →

The order we suggest

Section titled “The order we suggest”
  1. Finish Install and Connect an AI tool. Thirty minutes.
  2. Do Exercise 1 — four holes in a plate. Once a model comes out, you are ready.
  3. Pick the exercise closest to your own work. Have a drawing? 2, 3, 10 and 11. Vendor parts? 4 and 5. An existing model that keeps turning red? 6.
  4. When you get stuck, read Writing prompts, rewrite your sentence, and ask again. Questions go to GitHub Issues.

Things to know up front

Section titled “Things to know up front”
  • All traffic stays inside your PC (127.0.0.1). Your model files never leave the machine. Your AI tool, however, does send the conversation to its vendor’s servers.
  • The AI does not save files until you tell it to. When you like what you see, say “save it”.
  • Fix candidates always come back as a numbered list, and only the ones you pick get applied. Nothing is fixed automatically.
  • Everything here was verified on FreeCAD 1.1.3 · Windows. On macOS and Linux only the install paths differ; the steps are the same.