Pyraminx Edge Tutorial

As advertised at the end of my Master Pyraminx tutorial, the Pyraminx Edge is a modification of the Pyraminx – a tetrahedral scramble puzzle in the general category of Rubik's Cube-like things – also known as Jing's Pyraminx. Sorry, I have no information about its history, number of possible permutations or fastest-solved records. (Update: OK, it was invented by Adam Cowan in 2009). I can only attest that once clued in to the series of "down-down-up-up" patterns required to solve it, any frustration I had trying to figure it out without help turned into a sense that this puzzle is so easy, it practically solves itself.

Again, shapewise, it's a triangle-based pyramid with four equilateral sides, the simplest of the five Platonic solids. Puzzle-wise, it's really kind of a 2-layer Pyraminx (whereas the original has three layers), since its corners/tips can't turn by themselves. Each side is divided into three corners, three edges and one center; and while each side is cut for moves around three different axes, a move always takes one corner, two edges and the center as a unit, leaving the remaining edge and two corners behind.

Nevertheless, it has the same R, R', U, U', L, L', B and B' moves as the original Pyraminx. Here, for illustrative purposes, are the R, L, U and B steps respectively, starting from the "ready to scramble" position of yellow down and green at front.

Neither of the online scramble-pattern generators that I regularly consult has a scrambler for the Pyraminx Edge. No problem; I simply use the scrambler for the Pyraminx and do the lowercase corner moves (which are impossible) like they're capital-letter moves. Here's an example, in the scrambler and in reality:

STEP 1. Match up the corners on all four sides. This is so ridiculously intuitive, I'm embarrassed to say I didn't think to do this before I consulted a solution guide. Putting this step first cleared up every difficulty.

STEP 2. After choosing a side to put face-down (here I went with yellow), position an edge above the slot where it belongs, with the down color at front. Behold, the blue-yellow edge at left.

Then do that "down-down-up-up" thing you learned about in the Master Pyraminx tutorial. Remember? Alternating left and right, starting on the side with the piece in question? In this case, that would be an L R' L' R pattern.

Result: That blue-yellow edge is now snugly parked between the two blue-yellow corners, facing the right way. Here I do a similar move, only coming from the right, to put the yellow-red edge at front between the red-yellow corners at left.

This time "down-down-up-up" takes the form of R' L R L'. You don't need me to show you all those steps, so here's the result:

Here's an interesting case: The remaining bottom edge (yellow-green) is in the correct slot, but flipped the wrong way.

Solution: dial in one of the adjacent edges (I pulled from the right) to get the problem edge out of the way.

Then twist the edge in question so the down-side color faces front, and repeat the same algorithm to slot it in the right way around.

There's theoretically a STEP 3 in here, where you've solved the edges of the initial down-side and you move on to the remaining edges. You'd pretty much just match up the corners again, choose a different side to face down and proceed as before until all the edges are in place. But perversely, my example solve went so well that at the end of Step 2, all I had to do was a U move to match up the corners ...

... And I was ready for STEP 4: Permutating the centers. Hold the pyramid point-down with two centers that need to be swapped facing up and to the front:

Then do "down-down-up-up" three times, alternating left-right-left-right or right-left-right-left, your choice. Not to belabor it, here are just the beginning of the first move and the final result.

Seriously, this is never going to be a sanctioned event in speed-cubing competition. Once you achieve Step 1, with the corners sorted, the rest of the solve is as few as six, and perhaps as many as nine or ten, iterations of "down-down-up-up," give or take an occasional twist to restore the centers again. It's almost so easy that it could slip out of your hands and solve itself while tumbling across the floor. I'm not even sure if a puzzle so easy is worthy of a warm-up to an afternoon of higher-level puzzle solving. This might be the puzzle to give to someone who's scared they'll never figure out how to solve a 3D puzzle. Tell them "match up the corners" and explain the concept of "down-down-up-up" and they'll feel like a genius. Or maybe it's the one you use to cleanse your palate after a long, nasty struggle with Square-One. (Shudder. We'll get to that bastard eventually.)