3D CAD Skill

Use this skill for parametric 3D modeling tasks where geometry must be correct, manufacturable, and easy to revise.

When To Use It

Trigger this skill when the user asks for any of the following:

• A 3D printable or CAD-ready part
• OpenSCAD or build123d model generation
• Edits to an existing parametric model
• Shape debugging from screenshots, renders, or exported meshes
• Precise dimensions, fit checks, tolerances, wall thicknesses, or hole placement

Core Rule

Do not trust mental visualization of 3D geometry. Write code, render or export a view, inspect the result, then revise.

If the environment supports screenshots or image inspection, use them after every meaningful geometry change. If not, inspect through deterministic evidence such as orthographic projections, section cuts, bounding-box checks, and explicit dimension calculations.