Openscad

OpenSCAD Design Skill

Create versioned OpenSCAD files, render previews, and compare iterations for 3D printing designs.

Workflow

1. Determine the Next Version Number

Before creating a new .scad file, find existing versions:

.claude/skills/openscad/scripts/version-scad.sh <name>

This returns the next version number and filename. For example, if piano_001.scad exists, it returns piano_002.

2. Create the Versioned .scad File

Write the OpenSCAD code to the versioned filename (e.g., piano_002.scad).

3. Render the Preview

.claude/skills/preview-scad/scripts/render-scad.sh <name>_<version>.scad --output <name>_<version>.png

This creates a PNG with the matching version number (e.g., piano_002.png).

4. Compare with Previous Version

Read both the current and previous PNG images to visually compare:

• Current: piano_002.png
• Previous: piano_001.png (if exists)

Evaluate what changed and whether the new version better matches requirements.

5. Iterate

If the design needs improvement:

1. Analyze what's wrong
2. Create the next version (e.g., piano_003.scad)
3. Render and compare again

File Naming Convention

<model-name>_<version>.scad  ->  <model-name>_<version>.png

Examples:

• phone_stand_001.scad -> phone_stand_001.png
• phone_stand_002.scad -> phone_stand_002.png
• gear_001.scad -> gear_001.png

Use underscores in model names, and always use 3-digit zero-padded version numbers.

Example Session

User asks for a piano model:

1. Check for existing versions:

   .claude/skills/openscad/scripts/version-scad.sh piano
   

   Output: piano_001 (no existing files)

2. Write piano_001.scad with initial design

3. Render preview:

   .claude/skills/preview-scad/scripts/render-scad.sh piano_001.scad --output piano_001.png
   

4. Read piano_001.png to inspect the result

5. If improvements needed, create piano_002.scad, render to piano_002.png

6. Read both piano_001.png and piano_002.png to compare iterations

Render Options

See /preview-scad for full rendering options:

• --size <WxH> - Image dimensions (default: 800x600)
• --camera <x,y,z,tx,ty,tz,d> - Camera position
• --colorscheme <name> - Color scheme (default: Cornfield)
• --render - Full render mode (slower, more accurate)
• --preview - Preview mode (faster, default)

Next Steps

Once the design looks correct in PNG previews:

1. Export to STL: Use /export-stl to convert the final version to STL format
2. The export includes geometry validation to catch printability issues

Full Pipeline

/openscad → /preview-scad → /export-stl (with validation)

Tips

• Start simple and add complexity in iterations
• Use meaningful model names that describe the object
• Keep each version's changes focused on specific improvements
• Document what changed between versions in your response to the user
• Only export to STL once the preview looks correct
• Always run slice-check before considering a model print-ready