Hey twisty puzzlers,

It's been a while since I've posted a new puzzle. I've seen March and April go by without a single puzzle of mine in the "Puzzles of ____ 2011" thread. Well, my junior year of engineering school is done, and it's time to make some puzzles!

I would like to present my latest puzzle:

The Twisted Starminx
Check out the VIDEO!
Go bid in the AUCTION!


This puzzle is what you get if you leave your Starminx sitting in a hot car for too long, and then try to turn it.

Just kidding.

Right at the end of my Twisty Puzzles à la Vi video, I show 6 of my custom-made puzzles. Almost every time I've shown someone the video for the first time, they immediately notice the Twisted Cube, and say something like "Ooh I like that one!" This always surprised me, since I made the puzzle 2 years ago, and I've kind of gotten into the habit of thinking of 3x3 mods as something of the past. But since the audience liked the Twisted Cubes, I decided it was time to try twisting a different shape.

The obvious next choice was a dodecahedron, since there were so many great puzzles that could be made from it. Thus the Twisted Starminx was born.

To make this shape in SolidWorks, I used the Loft feature. It's a fun tool to mess around with, as with a few simple sketches and options, you can produce the craziest shapes. Go have fun with it!

This puzzle has 26 unique parts. Luckily, 20 of those parts are pairs of mirror-image pieces, but it still took me more than 6 hours to adjust, fillet, and shell them out. My poor MacBook Pro was begging for mercy by the time I was done.

The most interesting part of making this puzzle was cutting the stickers. On puzzles with flat faces, I just project the shapes of the pieces onto a sketch plane, and use those to define the shapes of the stickers for the laser-cutter. But when the surfaces are curved as strangely as they are on a twisted shape, it's impossible to get the sketch exactly right. On the Twisted Cubes, I just cut those stickers by hand. But the Twisted Starminx needed 172 stickers. So I ended up projecting three different groups of stickers on to 3 different planes, depending on the general orientation of the stickers. Then I cut some sample stickers, and used trial and error to adjust the shapes until they were just right. It was a lengthy ordeal, but it was worth it. This puzzle looks mighty fine.

The puzzle turns really, really well. Some of the pointy pieces catch occasionally, but that is the nature of puzzles with so many pieces. I am very happy with this mechanism.

This puzzle will be posted on eBay sometime in the next week or two.

Enjoy the rest of the pictures!

-Eitan

Awesome.

I see hexagonal symmetries and pentagonal symmetries. I think it's a mod of either a deeper cut icosahedral or dodecahedral puzzle, but I'm not sure.

Can't wait to find out though!

My bet is a Tuttminx shape mod. But I will love it for whatever it is. Will it be an eBay puzzle or will this one be a Shapeways puzzle?

Yea maybe Tuttminx shapemod. But its a print...

I think deep-cut edge turning rhombic doecahedron... seems familiar

Kapusta is the closest so far. One face left to sticker!

Oh, if I didn't have to be at a track meet in a half an hour I'd so help with the stickering.

I fail to see the pentagonal symmetry. I can only make out about a billion hexagons on that thing.

Thanks for the thought, but stickering is definitely a one-person job.

In any case, here it is! I'll update the first post later today.

Say hello to the Twisted Starminx:

Pentagonal Hexagonal

Hmm... interesting shape.

Very interesting puzzle Eitan! It's not my favourite from you, but it's pretty epic.

If I am looking at this correctly, it is "just" a shapemod of the Starminx I geometry, but because of the way the shape is shallower around parts of the equator than a normal Starminx I, there is an equatorial ring of "corners" from the internal pyraminx-crystal layer showing (which are the smallest triangles in the middles of the 10 weird faces). Those extra pieces make the neighboring Starminx I "edges" look hexagonal.

Very cool idea =) I would imagine solving it would be very confusing.

Exactly right. Thanks for the explanation.

-Eitan

sweet

NICE!!! Not sure how to go about making a shape like that. The top and bottom faces are planar. What are the other faces/surfaces? I don't believe they are conic or spherical.

Carl

The feature is called a "Loft" in SolidWorks. A loft creates a solid defined by a series of parallel sketches. (Though they might not have to be parallel. I've never tried. It is now on my list of cool things to try in SolidWorks.) This is the same way I made the Twister 1 and 2 waaaaay back when.

I'll post some screenshots of the process next time I'm on my Windows side.

-Eitan

Wow this is pretty awesome. Nice job!

Amazing! I like the shape.
To me, it looks like a 'normal' Starminx that's been cut down far enough for some of the corners to show... but it's probably wrong.

EDIT: ok, I'm now sure that I'm right, after singling out pieces and color coding them.
red = starminx edges
green = starminx centers
cyan = starminx 'petals' (points of the star)
yellow = corners (some are hidden so you can not see)

I've also highlighted the cuts.

I just updated the top post with information, pictures, and a video.

Enjoy!

-Eitan

Just watched the video... very very NICE!!!

And I was hit with a question. In the solved state some of the internal pyraminx-crystal corners are hidden.... so...

(1) Can these hidden corners become visable on the scrambled puzzle? I can't really tell from the video or the pics posted so far. I'm guessing yes. If so won't it be odd to have unstickered pieces moving around on the puzzle? Should or could they be stickered... maybe died the color of the planar face they are next to in the sloved state? That said, I guess the visable internal pyraminx-crystal corners could also become hidden as the puzzle is scrambled. Correct? If so I find that very interesting. I like the thought of a twisty puzzle where the inside and the surface are interchangeable

(2) Of the internal pyraminx-crystal corners that are seen are their surfaces a perfect equlateral triangle? I'm curious if these pieces contain orientation information due to their shape or not. If they do it appears to be very subtle. If a couple of these are rotated by 120 degrees from the solved state how hard is it to tell?

And not so related to the above two questions but this shape is obtained from taking a dodecahedron and twisting 2 opposite faces in opposite directions. I'm curious, what happens if you do the same twisting two opposite corners? Could all the faces be given the same shape that way?

Carl

I am actually glad you went with the Vinyl over the Meffert's style stickers on this one. That picture really didn't do this puzzle justice. That video... just wow. Wonderful puzzle Eitan congratulations on another job well done my friend!

Chris Hemerich

I really like your voice. I could listen to you talk about puzzles forever.

Fabulous puzzle Eitan!

I'm not sure if i like it though.....every time i see it, i want to ask it to dance.......and i'm pretty sure there's something not quite right about that!

Fantastic puzzle yet again. Very nice how a concept just leaps from the 3x3x3 to starminx. I don't recall any other puzzle that uses this same kind of shape.

If you ever plan to aution this one as unique, you could still put up the chiral version on shapeways

That sounds like a good idea, Sjoerd. I'll go make new designs for the Twisted Cubes when I have a chance. (The original design was for molding and casting, and I no longer use that method to make puzzles.)

I would like to get an idea of how many people would want copies of the Twisted Cubes. If you would be interested, please send me a PM.

-Eitan

I forgot to answer Carl's questions:

They can indeed be scrambled into a state where they are visible. Let me see if I can do it......... Yep, got it!



The exposed triangular PC corners come in two slightly different variations. The difference is so subtle that I decided to use 12 colors instead of 6 colors, so that the two versions would be different colors. (The two versions are mirror images of each other, so they appear on opposite sides of the puzzle. Hence they would have been stickered the same color if I had used 6 colors.)


That would be fantastic, but I have no idea how that could be done in SolidWorks. The shape I have here was made by exploiting the nature of the process by which you make a dodecahedron in SolidWorks. (See this tutorial for how I do it: http://www.solidworker.com/14/dodecahedron/)
Instead of using a simple extrude, I used a lofted extrude, which allowed me to make it twist. I'll try a few things to see if I can make it a different way.

Thanks for the great questions! Thanks to everyone for the great compliments!

-Eitan

This is a really cool application of the twisting concept. Definitely not something you expect as an early modification of a concept. Well made and very attractive. Good job.

Thanks guys!

By the way......

I just listed the Twisted Starminx on eBay! Good luck!
http://cgi.ebay.com/ws/eBayISAPI.dll?Vi ... 949wt_1065

-Eitan

Amazing job. Now all you need to do is make a twisted starminx II

Interestingly enough, the Twisted Starminx II will have a completely different look from this one. It'd be interesting to compare them side-by-side, even if it's just an image.