October 2, 2014

Stickman #5 (Borg Box)

I have long been an admirer of Stickman #5 (Borg Box), an amazing design by Robert Yarger: I finally had a chance to try it out at the 2011 RPP, thanks to Peter Wiltshire bringing his copy. It has eighty very intricate wooden pieces that hold together in the shape of a box. To open the box, you need to slide the pieces around, and once open you can completely disassemble the puzzle into its component pieces. I loved the way it looked, with the patchwork of pieces all locked together.

This seemed to me like an excellent candidate for 3D printing since no glue-up is required, plus I wanted a copy and it goes for a pretty penny at auction! Of course, nothing would quite be the same as the beauty and craftsmanship of the wood version, but I thought that a plastic version would still be a fun way to appreciate the design. (In case you don't read to the end, I was successful and this is now available for sale! Read the end for details.)

Robert was also interested in the idea, and was kind enough to loan me a prototype of the Borg Box that he had, which I could use to create the model. I'm not much of a 3D modeler, but fortunately this puzzle is based on a cubic grid so I could model it in BurrTools. The tricky part was making sure I had all the pieces correct, since it was too complicated of an assembly puzzle for BurrTools to solve without some help!

What I ended up using was a little-known feature of BurrTools where you can save a solved assembly as a new piece. I gave each piece a distinct color, and had BurrTools assemble each panel separately (with a few color specifications given as hints). Next, I exported each solved panel as its own multi-color piece, and assembled these 6 pieces into the final solution. Finally, using this final solution with the exact color specs of each piece, BurrTools was able to assemble the full puzzle.

Using this process, I was able to identify and correct any errors I made during the initial modeling of the pieces. This was great, so I didn't have to waste any money on printing! The interface is a bit tough to use, but you can actually manually slide the pieces around in virtual space to make sure things are interacting correctly.

So I went and ordered a copy from Shapeways and it turned out quite well! Here's the jumble of pieces I received. Assembling it wasn't all that hard since I had become extremely familiar with the design while modeling it. If you didn't know what you were doing, it would be quite a bear!

I had a bit of an issue with some of the pieces on the top and bottom panels not staying locked together with the runners on that panel, but a small tweak to the design fixed this issue.

The other issue was the fit: it was a bit too loose for my taste, so I tried printing a second copy with a somewhat smaller offset to see if that helped. Unfortunately, this copy was too tight! I started sanding the pieces to fit, but then realized I could just swap some of the pieces from my first model to get a great fit! This did the trick nicely. In the final Shapeways model, I went with this mixed offset approach to get as good of a fit as possible.

Currently I'm offering this for sale at $180 plus shipping, but Shapeways just announced a price increase which will raise the price to $340 after October 7th 2014. You can contact me with the contact me link if you're interested in ordering one. I'm not offering these directly from Shapeways since it is probably best to receive it assembled, and it requires a bit of sanding to get the fit just right.

I've also modeled Stickman Snowflake and have that available for sale (here) direct from Shapeways. The price on this one isn't going up by as much, since there are only six pieces. This is a really neat design with six pieces forming a box that can be completely disassembled. I love the way the corners spiral together on this one!