I am a huge fan of cuboids and when I heard the 6x6x6 was coming out one of my first thoughts was about which ones I could make out of it. The most obvious to me was a 5x5x6. When the 6x6x6 finally arrived though I was a bit disappointed with it and I didn't think it would be suitable.
It doesn't move very smoothly so it's very difficult to get a decent transformation out of it.
In May / June 2009 several new amazing cuboid puzzles appeared and this got me yearning to make another one myself. Even though I knew it wouldn't be great I felt I had to go for a 5x5x6. On the evening of Saturday 20th June 2009 I finished what is almost certainly the world's first 5x5x6 though it is a very rough prototype. I made it without the use of CAD or rapid prototyping. I had managed to destroy several 6x6x6 corners in the process and realised I should have gone for a fractionally smaller size. However the resulting puzzle was surprisingly good, especially considering the awkward movement of the underlying 6x6x6 V-Cube. All movements are possible though it sometimes catches and I suspect pops are quite likely. It is my intention to make one or two more at a later date and use what I have learned to improve the quality. I may remove the 'clicks' from the 6x6x6 before I start next time.
I decided to colour the puzzle with white opposite blue, red opposite orange and green opposite yellow. This works much better than the 'norm' since the 5x5 ends of the puzzle only ever mix with each other. That means it's better to use contrasting colours instead of similar ones. I have used standard Rubik's Cube style stickers.
The puzzle can't change shape since it doesn't obey the cuboid shape changing rule-
"A cuboid is capable of shape changing when ( two or more edge unit lengths are different and odd ) or ( two or more edge unit lengths are different and even ) excluding cuboids with a side of one."
As with everyone of my cuboids all cubies are cubic and there is no pillowing
In total I have made twelve fully functional cuboids. They are- 2x2x3 (micro), 2x2x4, 2x2x6, 2x2x7, 2x3x4, 3x3x4 (large), 3x3x4 (medium), 3x3x5, 3x4x4, 4x4x5, 4x4x6, 5x5x6.