A web-based CAD tool powered by Python (FastAPI, CadQuery) and JavaScript (Three.js).

• Pixi (for Python dependency management)
• Bun (for JavaScript and testing)

1. Install Python dependencies:

   pixi install

2. Install JavaScript dependencies:

   bun install

The easiest way to run the project is using the start script data:

bun start

This will:

• Start the Python FastAPI backend (with auto-reload).
• Start the Frontend server.
• Start the Logging service.
• Display logs in the console and save them to the logs/ folder.

Open http://localhost:8080 in your browser to use the tool.

To run the automated Puppeteer tests which verify the backend, frontend, and generation logic:

bun test

• Parametric Design: Adjust gear parameters (teeth count, diameter, thickness, etc.) in real-time.
• 3D Visualization: View the generated 3D model using Three.js with orbit controls.
• Download STL: Export the generated model for 3D printing.
• Logging: Centralized logs saved to the logs/ folder.

Creating a 3D model with CadQuery is simple and declarative. Here is a simplified snippet from backend/gear_generator.py:

import cadquery as cq

# Create the main gear body
wheel = cq.Workplane("XY").cylinder(thickness, outer_diameter / 2.0)
wheel = wheel.faces(">Z").workplane().hole(inner_diameter)

# Create a single tooth
tooth = (cq.Workplane("XY")
         .moveTo(outer_diameter / 2.0 - tooth_height, 0)
         .lineTo(outer_diameter / 2.0, tooth_width / 2.0)
         .lineTo(outer_diameter / 2.0, -tooth_width / 2.0)
         .close()
         .extrude(thickness))

# Pattern the teeth
teeth = cq.Workplane("XY")
for i in range(num_teeth):
    angle = i * 360.0 / num_teeth
    rotated_tooth = tooth.rotate((0, 0, 0), (0, 0, 1), angle)
    teeth = teeth.union(rotated_tooth)

# Combine everything
result = wheel.union(teeth)

This project serves as a reference implementation for connecting a custom web UI to a Python Computer-Aided Design (CAD) kernel.

Many engineering tools require:

1. Parametric Design: Users need to change values (like "number of teeth") and see results immediately.
2. Custom Interfaces: Standard CAD software UIs are complex. A custom web UI can focus exactly on the parameters that matter for a specific workflow.
3. Visual Feedback: Integrating Three.js allows for interactive 3D visualization without needing desktop software.

By using FastAPI to wrap CadQuery, we can expose the power of a scriptable CAD engine to any web frontend.

• backend/: Python FastAPI application and CadQuery logic.
• frontend/: Static HTML/JS frontend using Three.js and dat.GUI.
• test/: TypeScript verification tests and infrastructure.
• logs/: Application logs (timestamped).