Hey forum, I'm very happy to show you my latest puzzle, named the "Rhomdo"

Video


The puzzle is a face turning version of a trapezo-rhombic dodecahedron. The puzzle has 12 faces, six of which are rhombuses, and 6 of which are trapezoids. The puzzle has 9 distinct turning axis (in the same way the rubik's cube has 3). The shapes make up for some crazy jumbling. The stickers for this puzzle were cut by Eitan (Thanks for rushing it!)

How I came up with this puzzle is a little bit of a story, and I think its quite interesting. The original inspiration for this puzzle came from the rhombic dodecahedron skewb. If you turn any of the cuts by 60 degrees you will end up with the shape of the Rhomdo. I always wanted to make a face turning puzzle out of that shape, but I thought it was impossible because there were differing edge lengths. Then, when the two helicopter skewb puzzles were released, I knew this puzzle would be possible (after a 60 degree skewb turn on the helicopter skewb, jumbling moves are allowed). After that, the puzzle sat on the bottom of my to do list, until The constellation six was released.

The constellation six may seem totally irrelevant, but the Rhomdo and the constellation six are very related. When all of the discussion started about the constellation six, I was very interested in what could be done with the geometries involved, so I fired up solidworks. As it turns out, when you view the constellation six as an edge turning puzzle, the act of rotating an edge moves turning axis on the puzzle (this is why its easier to look at it as a vertex turning puzzle). If you take all of the possible axis positions on the constellation six (nine of them), and use them to make a shape, it naturally produces the same shape that you got by doing a 60 degree turn on a rhombic dodecahedron skewb.

Anyway, when the shape revealed itself to me for a second time, I knew i had to make a puzzle out of it, and this is the result. I hope you enjoy.


solved puzzle



showing a normal 180 degree turn on a rhombic face



showing one of the types of jumbling

Absolutely beautiful. I'm glad the stickers came out so well!

-Eitan

Wow, really nice!

Thanks for the background on its origin,

Dave

Nice!

There is surely some very interesting symmetry on this shape.
And the way it rotates and exchanges pieces is intriguing.
It would be great to see more of this!




Pantazis

Beautiful. That's all I can say. It looks phenominal.

Very puzzling.

It's good to see some of the more unusual shapes out there, being used. The pattern of cuts works really well.

The shape is a 'trapezo-rhombic dodecahedron'. Its dual has some square faces - I don't know if this puzzle would function in that form.

Very nice Eric, you're on a roll lately! This is one of my favorites from you.

Very nice puzzle. I think it's safe to assume that the trapezoid faces are isosceles?

Great looking puzzle!

DLitwin wrote:Thanks for the background on its origin

Yes, thank you. I love hearing about how all these great ideas are born.

Justin wrote:The shape is a 'trapezo-rhombic dodecahedron'. Its dual has some square faces - I don't know if this puzzle would function in that form.

And good job on finding the name of that shape. I love learning some new geometry. If you knew that name off the top of your head I'm very impressed. I'm not sure I'd have even known how to look it up. Here is a good question for the google team... I have a shape in my head and I want to know if its been named... what is the best way to google it?

Carl

This is a very cool puzzle!I love seeing all the cool new things coming from you. I would buy one if I didn't need a new phone, valentines day gift, Birthday gift and 6 month anniversary gifts. And if it were for sale.

I found this shape online by searching "shape with rhombic and trapezoid sides" it was the first thing to pop up.

Oh Eric, do you plan to release this onto Shapeways? I'd love to buy one.

This is really awesome. Very cool shape. It looks a little like something Oskar would make.

I like the shape this puzzle takes, it's like having a random shape and adding face-turns to it. Very original puzzle! Great work.
(PS- I also like how the short edge looks deceptively like a Megaminx )

There is a reason why the shape has a name. The puzzle you were originally playing around with was a rhombic dodecahedron and the partial turn is the same as a partial turn of its dual, the cuboctahedron. This results in a Johnson solid (http://en.wikipedia.org/wiki/Triangular_orthobicupola), so it could be said that this is a Johnson Dual, probably the first puzzle of one of these shapes. This opens up a whole new set of shapes.

Hey everyone, thanks for the kind words on the puzzle, I didn't find time during daylight to make a video, so here are a few more photos showing the jumbling(all of the photos show the puzzle in the same state). The puzzle actually jumbles quite easily. There are often multiple jumbling moves you can make, and its significantly increases the difficulty of trying to get the puzzle back into shape (not even taking into account trying to do a full solve). The photos do a decent job of showing how crazy this thing gets, but they just don't compare to looking at it, and being able to manipulate it with your hands. It's really disorientating, and keeping a frame of reference is a real challenge.

Holy cow, Eric! That's just scary!

-Eitan

I am frigthened Eric! Good job!

Amazing puzzle and mind numbing concept. I've been looking forward to this one since you first showed me the idea and I have to say it turned out really, really nice

Must be a bear to solve!

Just bumping to let everyone know that I have taken a video for the puzzle. It shows off the shape much better than the pictures do.

Video

Wow. After watching the video, the puzzle looks even cooler!