Each year we like to feature holiday themed technical tips to keep the end of year chaos at bay. This year, I was inspired by a wooden brain-teaser puzzle I saw at a local craft supply store. So I bought one, reverse-engineered it in SOLIDWORKS, and made some artistic changes to bring out the snowflake shape I saw hiding within.
This puzzle’s design is primarily a cubic shape. Notice the six rectangular pieces that correspond to each face of the cube. As it turns out, if you slice a cube perpendicular to the midpoint of its longest diagonal, you get a perfect regular hexagon! Hexagons are famous for being the natural crystalline structure of ice, and of course snowflakes!
I used the SOLIDWORKS multi-body part environment to help reverse engineer the overall puzzle shape into its 9 pieces, and then I remodeled those pieces as bottom-up parts to make further edits quicker and easier.
I then added a few cuts to the model to decorate the hexagon into looking more like a snowflake. It was helpful to use Edit Component within the assembly, so I could put the overall puzzle model into the isometric orientation (where the hexagon appears). I also made heavy use of reference planes defined Parallel to Screen. Here is the result: With ambient shadows turned on, you can see a little better how it is defined in 3D. Finally, I adjusted to models to add some clearance where they interlock, and we printed the pieces on one of our Stratasys FORTUS 250 printers. The pieces are very sturdy in ABS, and they fit together nice and tight. (The wooden puzzle I bought for $3 was pretty sloppy and almost falls apart when you shake it.)
If you’d like to see how it goes together, you can download the SOLIDWORKS models, which include an animated Exploded View. Or you can watch the video below. Or you can just print out the 9 pieces for yourself and see if you can figure it out. But that’s a little unfair, because when you buy the wooden one from the store, at least you have the advantage of learning how to take it apart, before you try to solve how to assemble it!