The first 4x4x6 cuboid was made in 2004 by Tony Fisher, based on an idea of Geert Hellings to modify a 4x4x4 to have two extra layers. Joshua has made a very generous offer and paid me to design a 3D printable 4x4x6, and make it open source.
Joshua's initial proposal was to make the design based on the Rubik's 4x4x4, but I suggested to use a completely new mechanism since it would most likely result in a much higher quality while not raising the cost very much.
This new mechanism works really well and the result puzzle is absolutely perfect. It turns smoothly and even cuts corners some. In the video it makes a quite loud squeaking noise but it has been getting better.
The SolidWorks file for this puzzle, as well as the STL files, are available from thingiverse
under a Creative Commons license.
Note: this puzzle comes as a DIY kit when ordered directly from Shapeways, which you will need to assemble yourself. You will also need to supply your own M3 screws and springs, as well as stickers (Cubesmith 4x4x4 stickers can be used). You can order an assembled and stickered puzzle from me directly (firstname.lastname@example.org
), but the assembling fee will be slightly higher than with other puzzles since there is very little markup on this puzzle to begin with.