3D CAD Skill — Progressive Refinement

Use this skill for parametric 3D modeling where geometry must be correct, manufacturable, and easy to revise. Design is inherently iterative — this skill treats generation and editing as a single unified loop, not separate tasks.

When To Use It

Trigger this skill when the user asks for:

• A 3D printable or CAD-ready part
• OpenSCAD or build123d model generation
• Edits to an existing parametric model
• Iterative refinement of a model through multiple rounds of feedback
• 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. One change at a time.