Magical Materials Monday: Unicorn Horns

For a long time I’ve wanted to craft enchanted items, shaping wondrous artifacts from magical materials like some kind of wizard. Unfortunately, most of the magic drained out of the world long ago, forcing me to craft my mystic relics with microcontrollers and LEDs instead of dragon scales and basilisk teeth.

Historically, one of the rarest and most powerful magical materials was the horn of the mythical unicorn. Prized for its ability to heal grievous wounds and neutralize even the most potent poisons, a unicorn horn would be the most valuable item in a monarch’s treasury.

On account of increased regulation to protect the endangered unicorn population, horns fetch unholy sums of money, if you can find one at all. The local retailers haven’t had one in stock in ages.

As an alternative, I turned to CAD software and 3D printing as a source of unicorn horns.

After a bit of brainstorming, I came up with the idea to create the shape of the horn by sweeping a 2-dimensional sketch around a spiraling path- perhaps a spiral wrapped around a cone.

That approach was wrong.

To create the correct shape, two cross-section sketches were needed- a larger one at the base of the horn and a smaller one at the tip. Both shapes were run through FreeCAD’s sweep tool, along a helical path. With a bit of experimentation, I came up with several very different styles of horn using four different cross section shapes.

With the models ready to go, I browsed my bin of 3D printer filament for an appropriate material and color before settling on plain white ABS plastic, which I thought ought to look nice even without painting. I used Slic3r’s spiral vase setting to print the horns as one continuous extrusion; this produced delicate, seashell-like structures that shone brightly when illuminated from inside with a colored LED.

Later, while trying to create some crystal prisms out of translucent green PETG, I ran one of my horn models on a whim. The result looked great when illuminated with a plain white LED.

From left to right: triangle cross section, oval, triangle again, Overlapping circles/’Venn diagram’, and three circles of different radii.

If you want a little bit of the magic for yourself, I’ve shared the models on Thingiverse: http://www.thingiverse.com/thing:2324675

Go download them and make your own magic!