1. OpenSCAD H.C. Lilly III, Comcast Cable

2. What is OpenSCAD? 2D and 3D CAD Modeling Tool The CAD tool for programmers Open Source Free www.openscad.org Pronunciation: Open – ESS – CAD

3. Who Are You? Who has been on a First Robotics team before? Who has used OpenSCAD? Who has written computer programs? Who has programmed in more than one computer language? Differences between computer languages

4. Primitive Shapes cube([4, 4, 8]); sphere(r=5, $fn=100); cylinder(h=8, r1=2, r2=4, $fn=100); polyhedron( points=[[-4, 0, -4], [4, 0, -4], [0, -4, 4], [0, 4, 4]], faces=[[0, 2, 1], [0, 1, 3], [1, 2, 3], [0, 3, 2]] );

5. Test1 Code // // OpenSCAD Test 1: Primitive Shapes // translate([8, -2, 0]) cube([4, 4, 8]); translate([-10, 0, 5]) sphere(r=5, $fn=100); translate([0, 10, 0]) cylinder(h=8, r1=2, r2=4, $fn=100); translate([0, -10, 4]) polyhedron( points=[[-4, 0, -4], [4, 0, -4], [0, -4, 4], [0, 4, 4]], faces=[[0, 2, 1], [0, 1, 3], [1, 2, 3], [0, 3, 2]] );

6. Think About It How can I make my part using only these four primitives? What shapes can you make with these primitives? Notes: Functions use named parameters Make programs clear to understand, with lots of comments Dimensions are in mm Right handed coordinate system

7. Transform Operators translate([5, 0, 0]) rotate([0, 30, 0]) color([0, 0.5, 0.5]) scale([0.5, 2, 1]) mirror([0, 0, 1]) And others…

8. Test2 Code // // OpenSCAD Test 2: Transform Operators // translate([5, 0, 0]) cylinder(h=8, r1=2, r2=4, $fn=100); translate([12, 0, 0]) rotate([0, 30, 0]) cylinder(h=8, r1=2, r2=4, $fn=100); translate([25, 0, 0]) color([0, 0.5, 0.5]) cylinder(h=8, r1=2, r2=4, $fn=100); translate([35, 0, 0]) scale([0.5, 2, 1]) cylinder(h=8, r1=2, r2=4, $fn=100); translate([45, 0, 0]) mirror([0, 0, 1]) cylinder(h=8, r1=2, r2=4, $fn=100);

9. Translate and Rotate Rotation is always done around the origin The order of translate() and rotate() operations is important translate([12, 0, 0]) rotate([0, 30, 60]) color(“red”) rotate([0, 30, 60]) translate([12, 0, 0]) color(“green”)

10. Test2b Code // // OpenSCAD Test 2b: translate() and rotate() // translate([12, 0, 0]) rotate([0, 30, 60]) color("red") cylinder(h=8, r1=2, r2=4, $fn=100); rotate([0, 30, 60]) translate([12, 0, 0]) color("green") cylinder(h=8, r1=2, r2=4, $fn=100);

11. Combination Operators union() difference() intersection()

12. Test3 Code // // OpenSCAD Test 3: Combination Operators // translate([8, 8, 0]) cylinder(h=8, r1=3, r2=5, $fn=100); translate([8, -8, 0]) cylinder(h=12, r=2, $fn=100); translate([24, 0, 0]) union() { cylinder(h=8, r1=3, r2=5, $fn=100); cylinder(h=12, r=2, $fn=100); } translate([36, 0, 0]) difference() { cylinder(h=8, r1=3, r2=5, $fn=100); cylinder(h=12, r=2, $fn=100); } translate([48, 0, 0]) difference() { cylinder(h=12, r=2, $fn=100); cylinder(h=8, r1=3, r2=5, $fn=100); } translate([60, 0, 0]) intersection() { cylinder(h=8, r1=3, r2=5, $fn=100); cylinder(h=12, r=2, $fn=100); }

13. Programming Constructs Variables Arithmetic Operators: + - * / % for(a=[1:6]) { } if ((a 4)) { } else { } Relational Operators: = > Logical Operators: && || !

14. Test4 Code // // OpenSCAD Test 4: Programming Constructs // height = 4; // for(variable=[start:end]) (front row) for(a=[1:6]) { translate([((a+3)*a)+3, 0, 0]) cylinder(h=height, r=a, $fn=100); } // for(variable=[vector]) (middle row) for(a=[2, 3, 5]) { translate([((a+3)*a)+3, 17, 0]) cylinder(h=height, r=a, $fn=100); } // logical and relational operators (back row) for(a=[1:6]) { if ((a 4)) { translate([((a+3)*a)+3, 34, 0]) cylinder(h=height*3, r=a, $fn=100); } else { translate([((a+3)*a)+3, 34, 0]) cylinder(h=height, r=a, $fn=100); }

15. Putting it all Together Build a Motor Mount

16. Test5 Code, part 1 // // OpenSCAD Test 5: Motor mounting bracket // // All dimensions in mm // Motor dimensions switch = 1; motorBodyRad = 30; motorBodyLen = 60; motorCollarRad = 15; motorCollarLen = motorBodyLen + 3; motorShaftRad = 2; motorShaftLen = motorBodyLen + 20; // Bracket dimensions th = 5; mountWidth = (motorBodyRad * 2) + (th * 2); mountHeight = (motorBodyRad * 2) + th; holeRad = 4;

17. Test5 Code, part 2 // Circle precision variable cpv = 50; // Motor if (switch) { translate([th, mountWidth/2, motorBodyRad+th]) rotate([0, 90, 0]) color("turquoise") union() { cylinder(h=motorBodyLen, r=motorBodyRad, $fn=cpv); cylinder(h=motorCollarLen, r=motorCollarRad, $fn=cpv); cylinder(h=motorShaftLen, r=motorShaftRad, $fn=cpv); }

18. Test5 Code, part 3 // Mounting Bracket // Back of Bracket difference() { cube([th*2, mountWidth, mountHeight]); translate([th, th, th+motorBodyRad]) cube([th+.001, motorBodyRad*2, mountWidth]); translate([th, mountWidth/2, motorBodyRad+th]) rotate([0, 90, 0]) cylinder(h=th+.001, r=motorBodyRad, $fn=cpv); }

19. Test5 Code, part 4 // Front of Bracket difference() { translate([motorBodyLen, 0, 0]) cube([th*2, mountWidth, mountHeight]); translate([motorBodyLen-.001, th, th+motorBodyRad]) cube([th+.001, motorBodyRad*2, mountWidth]); translate([motorBodyLen-.001, mountWidth/2, motorBodyRad+th]) rotate([0, 90, 0]) cylinder(h=th+.001, r=motorBodyRad, $fn=cpv); translate([motorBodyLen+th-.001, th+motorBodyRad-motorCollarRad, th+motorBodyRad]) cube([th+.002, motorCollarRad*2, mountWidth]); translate([motorBodyLen+th-.001, mountWidth/2, motorBodyRad+th]) rotate([0, 90, 0]) cylinder(h=th+.002, r=motorCollarRad, $fn=cpv); }

20. Test5 Code, part 5 // Bottom plate cube([motorBodyLen + (th * 2), mountWidth, th]); // Ears for (trn = [ [0, -th*3, mountHeight-th], [motorBodyLen-th*2, -th*3, mountHeight-th], [0, mountWidth-th, mountHeight-th], [motorBodyLen-th*2, mountWidth-th, mountHeight-th] ]) { translate(trn) difference() { cube([th*4, th*4, th]); translate([th*2, th*2, -.001]) cylinder(h=th+.002, r=holeRad, $fn=cpv); }

21. What Else? text(); statement User Programmed Functions User Programmed Modules Trigonometric Functions Arithmetic Functions echo(); statement

22. Complete Tool Chain Calipers: Measure parts OpenSCAD: Build digital model, export as.stl MakerBot Desktop: Import.stl, create.makerbot print file MakerBot 3D Printer: Print. makerbot file in plastic