OpenSCAD Quick Reference - Cheat Sheet

Keep this handy during all OpenSCAD work. For full documentation: https://openscad.org/documentation.html

Basic Shapes (Primitives)

cube([length, width, height]);          // rectangular box
cube([l, w, h], center = true);        // centered at origin

sphere(r = radius);                     // sphere by radius
sphere(d = diameter);                   // sphere by diameter

cylinder(h = height, r = radius);       // cylinder
cylinder(h = height, d = diameter);     // cylinder by diameter
cylinder(h = height, r1 = 5, r2 = 2);  // cone (different top/bottom radii)

$fn = 50;  // sets smoothness for spheres/cylinders (higher = smoother, slower)

Transformations

translate([x, y, z]) shape;             // move
rotate([x_deg, y_deg, z_deg]) shape;    // rotate
scale([x, y, z]) shape;                 // scale (1.5 = 150%)
mirror([1, 0, 0]) shape;               // mirror across YZ plane (use [0,1,0] for XZ, [0,0,1] for XY)

Boolean Operations

union() { shape1; shape2; }            // combine shapes
difference() { base; subtract; }       // remove one shape from another
intersection() { shape1; shape2; }     // keep only overlapping region

Tip for difference(): Always make the subtracting shape 1 mm taller on both ends than the base shape to avoid zero-thickness artifacts.

// Example - box with a hole:
difference() {
    cube([30, 30, 10]);
    translate([15, 15, -1]) cylinder(h = 12, r = 5);  // extends -1 to +11
}

Variables

length = 70;      // define a variable
width = 16;
height = 5;

cube([length, width, height]);    // use the variables
cube([length * 2, width, height]); // math works too

Modules (Reusable Functions)

// Define a module:
module my_box(l = 20, w = 15, h = 10) {
    cube([l, w, h]);
}

// Call the module:
my_box();               // uses all defaults
my_box(30, 20, 8);     // positional arguments
my_box(l = 50);         // named argument; others use defaults

Loops

// Repeat a shape N times:
for (i = [0 : 4]) {         // i goes 0, 1, 2, 3, 4
    translate([i * 20, 0, 0]) cube([15, 15, 5]);
}

// Step size:
for (i = [0 : 5 : 20]) {   // i goes 0, 5, 10, 15, 20
    translate([i, 0, 0]) sphere(r = 3);
}

2D Shapes (for extrusion)

circle(r = 10);            // 2D circle
square([w, h]);            // 2D rectangle
polygon([[0,0],[10,0],[5,10]]);  // arbitrary 2D shape

// Extrude a 2D shape into 3D:
linear_extrude(height = 5) circle(r = 10);  // makes a cylinder
rotate_extrude() translate([15, 0]) circle(r = 3);  // makes a torus

Useful Functions

len([a, b, c])         // returns 3 (length of a vector)
sqrt(25)               // returns 5
pow(2, 8)              // returns 256 (2^8)
abs(-5)                // returns 5
min(3, 5, 1)           // returns 1
max(3, 5, 1)           // returns 5

Comments

// Single-line comment

/*
  Multi-line
  comment
*/

Keyboard Shortcuts

Export Workflow

1. Press F6 (full render - wait for it to complete)
2. File > Export > Export as STL
3. Save with a descriptive filename: projectname_v2.stl

Sources

OpenSCAD. (n.d.). OpenSCAD cheatsheet. https://openscad.org/cheatsheet/
OpenSCAD. (n.d.). OpenSCAD documentation. https://openscad.org/documentation.html
Gohde, J., & Kintel, M. (2021). Programming with OpenSCAD. No Starch Press. https://nostarch.com/programmingopenscad