Coordinate Motion

Or is it “Coordinated Motion”? The latter makes more sense but the former seems to be the accepted term for describing burr-like puzzles whose assembly requires two or more pieces to be moved simultaneously and continuously. I guess I’ll just go with the flow and call them “coordinate motion puzzles.”

One of the most beautifully made puzzles I’ve ever come across, coordinate motion or otherwise, is the machined aluminum / joined wood / metal 3D printed version of Lee Krasnow’s “Slideways” puzzle. Just look at this:

I actually got to play with one at the 2018 Puzzle Design Competition and the smoothness of the sliding pieces is unbelievable. This and a bunch of other cool puzzles are available at Lee’s Etsy store. Also, if you have a 3D printer you can use this design on Thingiverse. I printed it out and I think it looks great:

Rooting around the internet for other coordinate motion puzzles, I came across a really elegant design by Viktor Genel, called “ReCube” (formerly known as “TriCube”). He has a blog where he posts about his projects and here are his two posts on the ReCube:

http://viktorg.com/wordpress1/2012/06/17/13-recube/
http://viktorg.com/wordpress1/2011/09/26/10-tricube-or-forward-to-past/

I have to admit the wireframe version looks pretty rad but I am more drawn to solid geometric shapes. I reverse engineered it (in OpenSCAD naturally) and then added some round indentations on the sides – I think they make it look more inviting to play with.

I recently saw a Kickstarter campaign for the “Venn” puzzle and it got me thinking: what would happen if I intersected the ReCube with a sphere? It may not be stainless steel like the Venn is, but I think this looks pretty cool:

One thing I really like about Viktor’s design is that the pieces do not have to be perfectly aligned before they will begin to slide into position. Many coordinate motion puzzles are really tough to assemble because all the pieces have to be lined up exactly right before you can start moving any of them. Plus, the assembly isn’t stable until all the pieces are slightly engaged. With Viktor’s design there’s some latitude with the initial positioning of the pieces so you don’t need infinite dexterity to assemble them.

As you can see I like the ReCube a lot. I reached out to Viktor and he gave me permission to put it up on my Shapeways shop – thank you Viktor! Both the cube version and the sphere version are available (and as soon as I get my newsletter working again I will send out an announcement.)