For the Boston 2016 Pride event, folks at work wanted to make a splash with some kind of costume appropriate for the event. We’re a software company (Autodesk) that makes design tools, so naturally we ought to use our stuff, and we ought to have some feature that is appropriate to the event. For the short short version of how to build it: download this file (or just use the line drawing here, or the SVG file if you have a giant laser cutter!), print it at about 3’x4’, trace it onto cardboard, cut/fold, attach the corners with tape, and cut yourself a head hole. More detailed instructions below.
Step 1: Making the Shape With Dynamo
Starting with Autodesk Dynamo Studio, we constructed a classic Platonic Solid called an Icosahedron. We liked this one because it's a polyhedral shape composed entirely of equilateral triangles (yay Pride iconography!)
We then used an unfolding algorithm to lay it out flat, adding cut and fold lines. If you install Dynamo Studio (or any other version of Dynamo) you can download the file from the Dynamo Package Manager in the Polyhedra package. Or grab the .dyn file directly from this link.
You can also try the same Dynamo file out on other shapes for more complex unfolding geometry. Big shout out to Mike Kirschner for his excellent Unfold library!
Step 2: Tracing and Cutting the Shape
After outputing this to a printable format at 3’x4’, we laid it out on a big piece of cardboard, and traced it (After a little trial and error, we found that an edge length of about 8” made a globe big enough for a head, but not too big for the neck.
Using the dotted lines at markers, we then cut out the outline of the shape and did partial cuts (scores) along the dotted lines.
Scoring makes for easier folding and nice crisp corners.
Be careful! Use a big straight edge that gives you plenty of distance between your hands and cutting instruments.
Step 3: Folding
By pre-folding the edges, it’s easier to do some fast and dirty masking tape sticking of the edges together on the inside of the hat.
After folding all the edges together, you get the 20 sided shape.
You can stop at this point, or reinforce the edges with additional tape. If you do this, you want to be a little more careful, as this will show even if you paint it.
Step 4: Cutting a Head Hole
Now for the head hole. You have to kind of free-hand this part, making a roughly oval shape spanning 2 triangles. Start small and try it out, then make it bigger and bigger until it fits.
If you make it too big, you can always wear a baseball cap between you and the cardboard.
You can finish off the edge of the head hole with more masking tape to soften it. If you are feeling fancy, get some pipe insulation.
Step 5: Decorating
Finally, when you get the size right, get busy with some paint, pipe-cleaners, stickers, crepe paper, fur, tin foil, whatever. Then stick it on your head and rock-out. Here are some of the variations by the awesome folks at the Autodesk Boston office!