A parametric Unicorn Horn, for attaching to the foreheads of things that need their awesomeness enhanced.

This is my first experiment with using OpenSCAD. A friend of mine is making an NES case mod and he needed a unicorn horn (don't ask). I searched through Thingiverse, but all I could find were prints for the pen plotter. Clearly, this needed to be fixed.

The design is just a parametric spiral with a bit of an offset to make it seem twisty and more natural. It's made entirely with blobs, which gives it a really cool texture when it prints.

I tried to put in pins for alignment, but I could never get them to print cleanly enough. The spiral was a good enough guide for me, but someone who's better at OpenSCAD might be able to get it to work.

I wanted a horn about 8 inches high, so I printed it in four pieces. I managed a 1/8th scale print as a single part, but it's basically too tall to print as one piece.

Here's what I did to print the horn.

1. Print the unicorn_horn_print.stl file. If you're really brave and your table doesn't shake like mine does, you might be able to get away with printing unicorn_horn.stl
2. Break off the bridges between the parts. A hobby knife helps to remove the ridges.
3. Sand the top and bottom of each piece flat. My printer curls the edges on the base pretty obviously, so it helps to sand the middle down a bit. Try to get the pieces flat and parallel or the horn will come out crooked.
4. Align the parts. The horn has a counter-clockwise spiral and the ridges from the print supports can help align the horn parts.
5. Superglue everything together. I pressed each section together, then let it set for ten minutes. Any gaps can be filled with superglue, which melts the ABS together and produces a nice finish.

After a little sanding, the horn looks pretty good.