Kidney Twisty Puzzle

I made this as a thank-you gift for the surgeon who did my nephrectomy. When I saw him walking around the hospital wearing a cap decorated with kidneys, I thought he might enjoy something like this.

It is not difficult to solve since it isn't a 3x3x3 like a Rubik's cube, but just 1x2x3. It's easy to assemble and difficult to take apart. No supports or hardware needed. Just 8 pieces to print.

Print two of the “H” shaped pins. They go into the hole of each of the center pieces (p3 and p4) insert with the short arms first. It will require some force to get them in, but they should snap in and then freely rotate in place. If it is too tight you may need to trim or sand the ends of the arms to fit.

Next, rotate pins to be perpendicular to each other and push the center pieces together part way. Make sure to put the end pieces into their slots before forcing the center parts all the way together.

Also see my variation on this model the Bent Kidney Puzzle where the cuts are oriented differently.