12 Sticks Puzzle

George W. Hart

Other Puzzles

Here is a puzzle consisting of 12 identical sticks that snap together in a tricky arrangement.
The colors show that you can see it as four triangles, so it is related to the four triangle puzzle.

Here is my first instance of it, made of ABS plastic on a Makerbot Cupcake.
You can see each piece is a rod with three notches at particular angles.

It looks very different from different viewpoints.  Above is the 4-fold view.

And here is the 3-fold view. 
You can see a few gaps in this image, so my stl file needs a bit of tweaking.

Now I've made a revised version in four colors. 
I tried dying uncolored ABS, but it came out rather splotchy.

Here's another view of it, looking down a 4-fold axis.
The assembly solution steps are shown here.
The stl file to make your own copy of it is available here.

References: This puzzle is in some ways similar to Geoff Wyvill's Nova Plexus puzzle.  But these four triangles are concentric, while Wyvill's puzzle is based on a different orderly tangle, with four non-concentric triangles. It is also very similar to Phillipe Dubois' Kubion, sold by Gaby Games, but its parts do not overlap at the ends and so have only the two central notches.  Thank you Nick Baxter for helping me track this down and for the Kubion photo. Also see Slocum and Botermans, Puzzles Old and New, p. 76.