In celebration of Maker Week, the Virginia Tech Northern Virginia Center hosted a 3DPrinting Day. This presentation is on how to use OpenSCAD (http://openscad.org) for 3D modeling.

1. 3D Design with OpenSCAD
Vicky Somma
vicky@tgaw.com
@TGAW
http://tgaw.wordpress.com
http://www.Shapeways.com/shops/tgaw
This presentation is on SlideShare at:
http://www.slideshare.net/VickyTGAW/3d-design-with-openscad

2. OpenSCAD – Download
• Free 3D Modeling Software
• Available for Windows, Linux, and MacOS
• Good at “clean” models (taking some of
worry out of the process– you can be
oblivious to “non-manifold” and “bad
face normals”)
• Because it’s instruction-base, it’s easy to
visualize measurements and come back
and tweak it
http://www.openscad.org/downloads.html

3. OpenSCAD – User Manual
Don’t Be Intimidated!
You Don’t Have to Memorize the Syntax!
Online User Manual
https://en.wikibooks.org/wiki/OpenSCAD_User_Manual
Quick Cheat Sheet
http://www.openscad.org/cheatsheet/

4. OpenSCAD – Anatomy of User Interface
Text Editor – Where we put our
instructions (“code”)
Viewing Area – Your handiwork!
Renders of the model.
Console – Technical information
about what’s going on (progress
on rendering, any error
messages)

5. OpenSCAD – Text Editor Commands
Icons to create new files, save, undo, redo, indent,
preview, render, and most importantly for 3D Printing--
export to STL format.

6. OpenSCAD – Text Editor to Viewing Area
To see how your work looks, you can:
• Use Preview ( ) or Render ( ) icons
• Use the Design->Preview or Design->Render menu options
• Or the fastest option - use F5 for Preview and F6 for Render

7. OpenSCAD – Viewing Area Commands
Commands for Viewing, Rendering, Zooming In, Changing Views, Turning On or Off
Axis and Measurements Display, Showing Edges Versus Faces

8. OpenSCAD – The Mouse & the Viewing Area
• Left clicking and dragging allows you to rotate your view
• Right clicking and dragging pans the view
• Scroll wheel allows you to zoom in and out

9. OpenSCAD – Syntax Common Themes
• ; - The end of an instruction (ie make a cube;)
• // - A comment or label– for your purposes– will be ignored by the
viewing area
• { } - Grouping of commands
• [x,y,z] – “Vectors” (Coordinates, 3D sizes)
Reference: https://en.wikibooks.org/wiki/OpenSCAD_User_Manual/General

10. OpenSCAD – Primitive Objects – Cube
cube([10,10,10]); cube([10,20,30]);cube([x, y, z]);
Draws 3D boxes
Not necessarily perfect
cubes – you can make
rectangles with it as well.
Reference: https://en.wikibooks.org/wiki/OpenSCAD_User_Manual/Primitive_Solids#cube

11. OpenSCAD – Primitive Objects – Cylinder
cylinder(r=10,h=22);
cylinder(r1=10,r2=3,h=22);
cylinder(r=x,h=z);
cylinder(r1=x,r2=y,h=z);
Draws cylinders – and not
necessarily perfect
cylinders
Reference: https://en.wikibooks.org/wiki/OpenSCAD_User_Manual/Primitive_Solids#cylinder

12. OpenSCAD – Primitive Objects – Cylinder
cylinder(r1=9, r2=0, h=9, $fn=4);
$fn parameter controls # of fragments
Increase– you can make really smooth objects
Decrease it– you can make Triangles, Pentagons, Pyramids, etc.
cylinder(r=9,$fn=3);cylinder(r=9,h=10,$fn=300);
Reference: https://en.wikibooks.org/wiki/OpenSCAD_User_Manual/Primitive_Solids#cylinder

13. OpenSCAD – Primitive Objects – Sphere
sphere(d=22); sphere(d=22, $fn=100);sphere(d=x);
Draws spheres – and you can
control resolution
$fn parameter controls how
smooth it looks
Reference: https://en.wikibooks.org/wiki/OpenSCAD_User_Manual/Primitive_Solids#sphere

14. OpenSCAD – Primitive Objects
You can build a lot out of standard shapes

15. OpenSCAD – Primitive Objects
You can build a lot out of these standard shapes- “Bipedal Mech” by Mathew Ridge
http://shpws.me/GQX5

16. OpenSCAD – 2D Objects - Text
text("TGAW");
Text(“x”);
Draws text. Text is great for customizing your models, engraving,
and embossing.
Reference: https://en.wikibooks.org/wiki/OpenSCAD_User_Manual/Text

17. OpenSCAD – 2D Objects - Text
Text(“x”, Font=“Font Name”);
Since OpenSCAD is installed on your machine, you can use any font already on your machine!
text("TGAW", font="Rockwell Extra Bold");
text("TGAW", font="Old English Text MT");
text("TGAW", font="Wingdings");
Reference: https://en.wikibooks.org/wiki/OpenSCAD_User_Manual/Text

18. OpenSCAD – 2D Objects - Polygons
polygon([[-24,0],[0,0],[0,32]
,[-16,32],[-15,28],[-13,24]
,[-12,20],[-12,15],[-13,10]
,[-15,6],[-19,3]]);
Polygon([x1,y1],[x2,y2],etc);
You specify the points to make
customized shapes (which you can
then extrude to 3D if needed)
Reference: https://en.wikibooks.org/wiki/OpenSCAD_User_Manual/2D_Primitives#polygon

19. OpenSCAD – 2D Objects - Polygons
Need visual help making
Polygons?
http://daid.eu/~daid/3d
A graphical interface that
builds your polygon code for
you.

20. OpenSCAD – 2D to 3D
linear_extrude(height = 10)
polygon([[-24,0],[0,0],[0,32],[-16,32]
,[-15,28],[-13,24],[-12,20],[-12,15]
,[-13,10],[-15,6],[-19,3]]);
Linear_Extrude(height=x)
Makes your 2D object (circle, square, polygon) 3D
It can even twist the object as it grows up
NO SEMICOLON AFTER IT
(It’s not the end of the statement– we have to tell it what to extrude)
Reference: https://en.wikibooks.org/wiki/OpenSCAD_User_Manual/2D_to_3D_Extrusion#Linear_Extrude

21. OpenSCAD – 2D to 3D
linear_extrude(height = 20, center = false
, $fn = 100, twist=30)
text("TGAW");
Linear_Extrude(height=x, twist=degrees)
Works on text and you can do fancy stuff like twisting
Reference: https://en.wikibooks.org/wiki/OpenSCAD_User_Manual/2D_to_3D_Extrusion#Linear_Extrude

22. OpenSCAD – 2D to 3D
rotate_extrude(convexity = 10, $fn=300)
polygon([[-24,0],[0,0],[0,32],[-16,32],[-15,28]
,[13,24],[-12,20],[-12,15],[-13,10]
,[-15,6],[-19,3]]);
Rotate_Extrude()
Your 2D object (circle,
square, polygon) is rotated
around to make a 3D object
(like a cross section)
NO SEMICOLON AFTER IT
It’s not the end of the statement-- we need to tell it
what to extrude.
Reference: https://en.wikibooks.org/wiki/OpenSCAD_User_Manual/2D_to_3D_Extrusion#Rotate_Extrude

23. OpenSCAD – Import STL
import("C:DownloadsVT.stl",convexity=10);
import(filepath, convexity=10);
The import function lets you bring in
existing 3D models into your project.
Note: In Your filepath, backslashes need to be doubled.
C:DownloadsMyStl.stl -> C:DownloadsMyStl.stl
Tip: If you are using other people’s models, be sure to
check and respect their licensing
(http://www.thingiverse.com/thing:818805 by GlynnLo)
Reference: https://en.wikibooks.org/wiki/OpenSCAD_User_Manual/Importing_Geometry

24. OpenSCAD Basics – Transformations - Translate
cube([22,22,5]);
sphere(d=22, $fn=100);
cube([22,22,5]);
translate([11,11,0])
sphere(d=22, $fn=100);
translate([x,y,z])
Translate MOVES objects– lets you
define the how far to move along
each of the axes.
NO SEMICOLON AFTER IT
(It’s not the end of the statement– we have to tell it what to translate)
Reference: https://en.wikibooks.org/wiki/OpenSCAD_User_Manual/Transformations#translate

25. OpenSCAD – Transformations – Rotate
rotate([x,y,z])
Rotate angles the object.
Guide to the axis is in your preview panel
NO SEMICOLON AFTER IT
(It’s not the end of the statement– we have to tell it what to rotate)
It’s Okay if you Need Some Trial and Error : )
Reference: https://en.wikibooks.org/wiki/OpenSCAD_User_Manual/Transformations#rotate

26. OpenSCAD - Transformations – Rotate
rotate([0,-45,0])
cube([22,22,5]);
rotate([0,0,30])
cube([22,22,5]);
rotate([x,y,z])
rotate([30,-45,30])
cube([22,22,5]);
Reference: https://en.wikibooks.org/wiki/OpenSCAD_User_Manual/Transformations#rotate

27. OpenSCAD - Transformations – Resize
resize([x,y,z],auto=true|false)
Resize allows you to make your object different
sizes where x, y, and z are your new dimensions
NO SEMICOLON AFTER IT
(It’s not the end of the statement– we have to tell it what to resize)
If auto=false, anything left zero stays the same.
If auto=true, anything left zero is sized proportionally. resize([200,0,10], auto=true)
import("VT.stl", convexity=10);
resize([200,0,10], auto=false)
import("VT.stl", convexity=10);
import("VT.stl", convexity=10);
Reference: https://en.wikibooks.org/wiki/OpenSCAD_User_Manual/Transformations#resize

28. OpenSCAD – CSG Modeling
CSG stands for Constructive Solid Geometry.  You don’t need to remember that
Do Remember:
• Powerful!
• Combines your primitive parts/objects.
• Adding, Subtracting, Intersections
Credit: https://en.wikipedia.org/wiki/Constructive_solid_geometry#/media/File:Csg_tree.png
Reference: https://en.wikibooks.org/wiki/OpenSCAD_User_Manual/CSG_Modelling

29. OpenSCAD – CSG Modeling - Union
Adds objects into a one
union ()
{
object1;
object2;
}
union()
{
cube([5,10,5]);
translate([5,10,2.5])
{
rotate([0,-90,0])
cylinder(d=5, h=5, $fn=30);
}
translate([5,0,2.5])
{
rotate([0,-90,0])
cylinder(d=5, h=5, $fn=30);
}
}
Two cylinders and a cube
After union – single rounded object
Reference: https://en.wikibooks.org/wiki/OpenSCAD_User_Manual/CSG_Modelling#union

30. OpenSCAD – CSG Modeling - Difference
Subtracts objects from each other
difference ()
{
object1;
object2;
}
difference()
{
cube([5,10,5]);
translate([5.5,10,2.5])
{
rotate([0,-90,0])
cylinder(d=5, h=6, $fn=30);
}
translate([5.5,-1,2.5])
{
rotate([0,-90,0])
cylinder(d=5, h=6, $fn=30);
}
}
Two cylinders and a cube
After “subtracting” the cylinders from
the cube
Reference: https://en.wikibooks.org/wiki/OpenSCAD_User_Manual/CSG_Modelling#difference

31. OpenSCAD – CSG Modeling - Difference
Practical Use of Difference – Engraving Text!
difference()
{
cube([5,10,5]);
translate([5.5,10,2.5])
{
rotate([0,-90,0])
cylinder(d=5, h=6, $fn=30);
}
translate([5.5,-1,2.5])
{
rotate([0,-90,0])
cylinder(d=5, h=6, $fn=30);
}
translate([2,6.5,0.5])
rotate([90,0,-90])
linear_extrude(height=2)
text("V", font="Old English Text MT", size=4);
}
Reference: https://en.wikibooks.org/wiki/OpenSCAD_User_Manual/CSG_Modelling#difference

32. OpenSCAD – CSG Modeling - Intersection
Takes where both objects overlap
(like a Venn Diagram)
intersection ()
{
object1;
object2;
}
intersection()
{
cylinder(r=5,h=3);
translate([4,0,0])
cylinder(r=5, h=3);
}
Two cylinders
Intersection – an Almond Shape
Reference: https://en.wikibooks.org/wiki/OpenSCAD_User_Manual/CSG_Modelling#intersection

33. OpenSCAD – CSG Modeling - Intersection
Practical Use of Intersection – Curving Details!
intersection()
{
sphere(r=9.25, $fn=100);
resize([0,0,11],auto=false)
resize([12,0,0], auto=true)
import("VT.stl", convexity=10);
}
A sphere and a VT Logo Intersection – A curved VT Logo
Reference: https://en.wikibooks.org/wiki/OpenSCAD_User_Manual/CSG_Modelling#intersection

34. OpenSCAD – CSG Modeling - Combinations
Practical Use of Intersection – Curving Details!
union()
{
sphere(r=9, $fn=100);
intersection()
{
sphere(r=9.25, $fn=100);
resize([0,0,11],auto=false)
resize([12,0,0], auto=true)
import("VT.stl", convexity=10);
}
}
Add a slightly smaller sphere and we have a curved, embossed VT logo on a sphere.
Reference: https://en.wikibooks.org/wiki/OpenSCAD_User_Manual/CSG_Modelling

35. OpenSCAD – Advanced - Modules
To help readability and reusability, you can make modules.
module name()
{ //your code }
module base_sphere()
{
sphere(r=9, $fn=100);
}
module curved_VT()
{
intersection()
{
sphere(r=9.25, $fn=100);
resize([0,0,11],auto=false)
resize([12,0,0], auto=true)
import("VT.stl", convexity=10);
}
}
union()
{
base_sphere();
curved_VT();
}
union()
{
sphere(r=9, $fn=100);
intersection()
{
sphere(r=9.25, $fn=100);
resize([0,0,11],auto=false)
resize([12,0,0], auto=true)
import("VT.stl", convexity=10);
}
}
Reference: https://en.wikibooks.org/wiki/OpenSCAD_User_Manual/Modules
Fun Fact – All objects in a model are already merged into one, no
unions necessary

36. OpenSCAD – Advanced - Loops
Loops are powerful for repeated tasks
for ( i = [start : increment : end] )
{ //your code }
for (i=[0:5:15])
{
translate([i,0,0])
cylinder(r=1, h=15, $fn=36);
}
Translation– We are going to start at 0. Every 5 mm, draw a
cylinder until we reach 15mm.
Reference: https://en.wikibooks.org/wiki/OpenSCAD_User_Manual/Conditional_and_Iterator_Functions#For_Loop

37. OpenSCAD – Advanced - Loops
“Nested Loops”
for ( i = [start : increment : end], j = [start : increment : end] )
{ //your code }
for (i=[0:5:15],j=[0:5:20])
{
translate([i,j,0])
cylinder(r=1, h=15, $fn=36);
}
Translation– We going to end up with 20 pegs in 4 columns
and 5 rows.
Reference: https://en.wikibooks.org/wiki/OpenSCAD_User_Manual/Conditional_and_Iterator_Functions#For_Loop

38. OpenSCAD – Troubleshooting
Having Unexpected Results?
• Check Your Syntax
(maybe there’s a semi colon after a translate)
• Check the Console for error messages (which would include a
line number)

39. OpenSCAD – Troubleshooting
• echo allows you to send details to the Console
• // allows you to comment out instructions so you can narrow
down the culprit
echo("i:", i, " j:", j);

40. OpenSCAD – Troubleshooting
• # allows you to have objects highlighted
difference()
{
cube([5,10,5]);
translate([5.5,10,2.5])
{
rotate([0,-90,0])
cylinder(d=5, h=6, $fn=30);
}
translate([5.5,-1,2.5])
{
#rotate([0,-90,0])
cylinder(d=5, h=6, $fn=30);
}
}

41. OpenSCAD – Saving and Exporting
• Be sure to Save your code often
• When you’re ready to print, you’ll want to Export to STL file.
• Pre-requisite– Do your official render (F6).
• The system will remind you. : )

42. OpenSCAD – Code Scavenging!
OpenSCAD even comes
with its OWN examples
which you can open,
review, and tweak to
meet your needs.

43. OpenSCAD – Code Scavenging!
Thingiverse has a OpenSCAD area full
of shared source code– just search
“OpenSCAD”
http://www.thingiverse.com/search?q
=OpenSCAD
You can download the final .STL file
AND the original .SCAD files, so you
can read and find out how it was
made.

44. OpenSCAD – Code Scavenging!
• OpenSCAD Community Forums
http://www.openscad.org/community.html
• OpenSCAD reddit
http://www.reddit.com/r/OpenSCAD/
• Good ole Google

45. OpenSCAD – OpenJSCAD
http://openjscad.org
• Web-based
• Has its own JavaScript, object-oriented
language
• BUT 95% of the OpenSCAD Language is
supported
Quick Tips
• User Guide at
https://github.com/Spiritdude/OpenJSCAD.org/wiki/User-Guide
• //!OpenSCAD at the top tells it you’re using OpenSCAD
• Shift-Enter in the “Text Editor” renders
• Holding down the Left or Right Mouse Button lets you rotate the
View Pane
• Holding down Shift Left Mouse Button lets you pan in the View Pane

46. THANK YOU!!!
https://twitter.com/tgaw
http://tgaw.wordpress.com
http://www.shapeways.com/shops/tgaw
http://www.instructables.com/member/VickyTGAW
http://instagram.com/VickyTGAW
Vicky Somma
vicky@tgaw.com