OpenSCAD Cheat Sheet: Essential Commands for 3D Modeling

Published: February 21, 2026

Quick Reference Overview

This is the cheat sheet I wish I'd had when learning OpenSCAD. Bookmark it—you'll be back. If you're brand new, check out our OpenSCAD Tutorial first, or generate OpenSCAD code from a photo and learn by studying real examples.

🔲 3D Primitives

Your building blocks. Everything complex starts with these:

Command	Description	Example
`cube(size)`	Creates a cube or box	`cube(10);` or `cube([10, 20, 5]);`
`sphere(r)`	Creates a sphere	`sphere(r=15);` or `sphere(d=30);`
`cylinder(h, r)`	Creates a cylinder or cone	`cylinder(h=20, r=10);`
`cylinder(h, r1, r2)`	Creates a cone/tapered cylinder	`cylinder(h=20, r1=15, r2=5);`
`polyhedron(points, faces)`	Creates custom 3D shape from vertices	`polyhedron(points=[[...]], faces=[[...]]);`

// Cube with size [width, depth, height]

cube([30, 20, 10]);

// Centered cube

cube([30, 20, 10], center=true);

// Smooth sphere ($fn controls resolution)

sphere(r=10, $fn=64);

◻️ 2D Primitives

Flat shapes you'll extrude into 3D later:

Command	Description	Example
`square(size)`	Creates a rectangle	`square([20, 10]);`
`circle(r)`	Creates a circle	`circle(r=10, $fn=64);`
`polygon(points)`	Creates custom 2D shape	`polygon([[0,0], [10,0], [5,10]]);`
`text(str)`	Creates 2D text	`text("Hello", size=10);`

↕️ Extrusion (2D → 3D)

Turn flat shapes into 3D. This is where the magic happens:

Command	Description	Example
`linear_extrude(height)`	Extrude 2D shape straight up	`linear_extrude(10) circle(r=5);`
`linear_extrude(height, twist)`	Extrude with rotation	`linear_extrude(20, twist=90) square(10);`
`linear_extrude(height, scale)`	Extrude with taper	`linear_extrude(20, scale=0.5) circle(10);`
`rotate_extrude()`	Spin 2D shape around Z axis	`rotate_extrude() translate([10,0]) circle(3);`

// 3D text

linear_extrude(5)

    text("OpenSCAD", size=12, font="Arial:style=Bold");

// Twisted column

linear_extrude(50, twist=180, $fn=64)

    square([10, 10], center=true);

🔄 Transformations

Position things where you want them:

Command	Description	Example
`translate([x, y, z])`	Move object	`translate([10, 0, 5]) cube(5);`
`rotate([x, y, z])`	Rotate around axes (degrees)	`rotate([0, 0, 45]) cube(10);`
`scale([x, y, z])`	Resize object	`scale([2, 1, 0.5]) cube(10);`
`mirror([x, y, z])`	Mirror across plane	`mirror([1, 0, 0]) cube(10);`
`resize([x, y, z])`	Resize to exact dimensions	`resize([20, 20, 0], auto=true) sphere(10);`
`color("name")`	Set preview color	`color("red") cube(10);`

🔗 Boolean Operations (CSG)

The heart of OpenSCAD. Combine simple shapes into complex ones:

Command	Description	Use Case
`union()`	Combine shapes together	Join multiple parts into one
`difference()`	Subtract subsequent shapes from first	Create holes, cutouts
`intersection()`	Keep only overlapping regions	Create complex shapes from overlaps

// Cube with a cylindrical hole

difference() {

    cube([20, 20, 10], center=true);

    cylinder(h=12, r=5, center=true, $fn=32);

}

// Two overlapping spheres combined

union() {

    sphere(r=10);

    translate([8, 0, 0]) sphere(r=10);

}

📦 Modules (Reusable Components)

Don't repeat yourself. Define a shape once, use it everywhere:

// Define a module

module rounded_box(size, radius) {

    minkowski() {

        cube([size[0]-radius*2, size[1]-radius*2, size[2]/2]);

        cylinder(r=radius, h=size[2]/2, $fn=32);

    }

}

// Use the module

rounded_box([30, 20, 10], 3);

🔁 Loops and Conditionals

Generate patterns, arrays, and conditional features:

// Create a row of cylinders

for (i = [0 : 5]) {

    translate([i * 15, 0, 0])

        cylinder(h=10, r=5);

}

// Circular array

for (i = [0 : 360/6 : 360]) {

    rotate([0, 0, i])

        translate([20, 0, 0])

            cylinder(h=5, r=3);

}

// Conditional geometry

if (add_hole) {

    difference() {

        cube(20);

        cylinder(h=22, r=5);

    }

} else {

    cube(20);

}

⚙️ Special Variables

Variable	Description	Typical Value
`$fn`	Number of fragments (resolution)	`$fn=64` for smooth curves
`$fa`	Minimum angle for fragment	`$fa=1` (degrees)
`$fs`	Minimum size of fragment	`$fs=0.5` (mm)

Pro tip: Use $fn=32 while designing (previews render in seconds). Bump it to $fn=128 or higher only for your final export—otherwise you're just watching progress bars.

⌨️ Keyboard Shortcuts

Shortcut	Action
F5	Preview (fast, approximate)
F6	Render (slow, accurate)
F7	Export STL
Ctrl + D	Comment/uncomment line
Ctrl + Shift + V	View all (reset camera)

💡 Pro Tips

Debug visually: Prefix shapes with % to make them transparent, or # to highlight them red. Saves tons of head-scratching.
Speed vs. quality: Low $fn while working, high $fn only at the end
DRY principle: If you're copy-pasting geometry, make it a module instead
Comment everything: Future you won't remember what translate([37.5, 0, 0]) was for
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