openscad-modeler

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OpenSCAD 3D modeling assistant for creating and modifying parametric 3D models. Use when working with .scad files, making adjustments to 3D models (resizing, adding/removing sections, holes, fillets), creating new OpenSCAD geometry, or debugging OpenSCAD code. Supplements the openscad MCP server (mcp__openscad__render_single) with language knowledge and modification patterns.

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[Code Generation]

When & Why to Use This Skill

The OpenSCAD Modeler is a specialized Claude skill designed for parametric 3D modeling and CAD development. It enables users to create, modify, and debug .scad files through natural language, streamlining the transition from conceptual design to 3D-printable geometry. By integrating with the OpenSCAD MCP server, it provides real-time rendering and expert-level code patterns for complex boolean operations, transformations, and procedural modeling, making it an essential tool for engineers and 3D printing enthusiasts.

Use Cases

  • Parametric Prototyping: Rapidly generate 3D parts with adjustable parameters (variables) for engineering and rapid prototyping.
  • Geometric Modification: Easily add functional features like screw holes, fillets, chamfers, or custom cutouts to existing .scad models.
  • Script Debugging: Analyze and fix logical errors, syntax issues, or rendering artifacts in complex OpenSCAD codebases.
  • Procedural Generation: Create intricate patterns, arrays, and mathematical structures that are difficult to design in traditional mouse-driven CAD software.
  • Format Conversion & Optimization: Refactor existing geometry into cleaner, more efficient OpenSCAD code using modules and functions.
nameopenscad-modeler
descriptionOpenSCAD 3D modeling assistant for creating and modifying parametric 3D models. Use when working with .scad files, making adjustments to 3D models (resizing, adding/removing sections, holes, fillets), creating new OpenSCAD geometry, or debugging OpenSCAD code. Supplements the openscad MCP server (mcp__openscad__render_single) with language knowledge and modification patterns.

OpenSCAD Modeler

Workflow for creating and modifying OpenSCAD parametric 3D models.

MCP Integration

Use mcp__openscad__render_single to preview changes:

scad_content: "cube([10,10,10]);"    // Inline code
scad_file: "/path/to/file.scad"     // Or file path
view: "isometric"                    // front/back/left/right/top/bottom/isometric

Render after each significant modification to verify results.

Quick Reference

Primitives

cube([x,y,z], center=true);
sphere(r=5); sphere(d=10);
cylinder(h=10, r=5); cylinder(h=10, r1=5, r2=3);  // cone

Transforms

translate([x,y,z]) obj;
rotate([x,y,z]) obj;        // degrees
scale([x,y,z]) obj;
mirror([1,0,0]) obj;        // mirror across YZ plane

Boolean Operations

difference() { base; subtract1; subtract2; }  // Remove
union() { obj1; obj2; }                        // Combine
intersection() { obj1; obj2; }                 // Keep overlap

Extrusions

linear_extrude(height=10) circle(r=5);
linear_extrude(h=10, twist=90, scale=0.5) square(10);
rotate_extrude() translate([10,0]) circle(r=3);  // Torus

Resolution

$fn = 100;  // Smooth curves (set globally or per-object)
cylinder(h=10, r=5, $fn=6);  // Hexagon

Common Modifications

Add hole

difference() {
    existing_part();
    translate([x,y,z]) cylinder(d=hole_d, h=99, center=true);
}

Resize

scale([1.5, 1.5, 1]) existing_part();     // 150% XY, keep Z
resize([50, 0, 0], auto=true) part();     // 50mm wide, proportional

Round edges

minkowski() {
    cube([w-2*r, d-2*r, h-2*r], center=true);
    sphere(r=r);
}

Shell/hollow

difference() {
    outer_shape();
    offset(-wall) outer_shape();  // 2D
    // Or for 3D: scale down slightly
}

Array

for (i = [0:count-1]) translate([i*spacing, 0, 0]) part();
for (i = [0:5]) rotate([0, 0, i*60]) translate([r, 0, 0]) part();

Workflow

  1. Read existing .scad file or start new
  2. Identify what to modify (add/remove/resize)
  3. Apply appropriate pattern from above
  4. Render with MCP to verify (view: "isometric")
  5. Iterate as needed

Detailed References

Debugging Tips

  • Use # prefix to highlight object in preview: #cube([10,10,10]);
  • Use % for transparent preview: %cylinder(h=20, r=5);
  • Use ! to show only that object: !sphere(r=10);
  • Use * to disable object: *cube([10,10,10]);
  • Check $preview for render vs preview mode
  • Increase convexity parameter if preview renders incorrectly