HackyChristmas.github.io

Day 1

Today’s challenge consists of two parts:

• Download and install OpenSCAD
• Build a snowman

Download and Install OpenSCAD

Head over to the OpenSCAD website, download the version of OpenSCAD for the type of computer you’re using and install it (if the computer is not yours, you’ll need permission - and possibly some help - to do this).

Build a Snowman

Start OpenSCAD. You will see a window that’s split vertically into two parts:

• A left hand panel labelled ‘Editor’
• A right hand panel showing some scale lines (possibly with a ‘Console’ panel beneath it)

Click in the Editor window so it has the keyboard focus and copy the following code into it:

translate([0,0,50]) sphere(r = 50);
translate([0,0,120]) sphere(r = 25);
translate([0,0,135]) cylinder(r = 30, h =  2);
translate([0,0,135]) cylinder(r1 = 20, r2 = 25, h =  40);

Now press F5 (or the Preview button in the button bar) and a snowman should appear on the model view on the right hand of the screen.

What’s that all about, then?

The program above draws four shapes; two spheres and two cylinders. For each shape, we’re giving OpenSCAD two sets of information:

• Where to put the shape (this is what translate... does)
• What radius (and height, in the case of the cylinders) to draw the shape with

Let’s look at each line in turn:

• translate([0,0,50]) sphere(r = 50); // move to 50mm above the origin (the middle of our scene), and place a sphere with radius 50mm. This is the body of our snowman.
• translate([0,0,120]) sphere(r = 25); // move to 120mm above the origin and place a sphere with radius 25mm. This is the head of our snowman.
• translate([0,0,135]) cylinder(r = 30, h = 2); // move to 135mm above the origin and place a cylinder with radius 30mm and height 2mm. This is the brim of the snowman’s hat.
• translate([0,0,135]) cylinder(r1 = 20, r2 = 25, h = 40); // move to 135mm above the origin (notice this is the same start point as the brim) and place a cylinder with a start radius of 20mm, an end radius of 25mm and a height of 40mm. This is the rest of the snowman’s hat.

Nearly there…

Now save the file somewhere on your computer (remember where - we’ll use this again soon). And you’re done!