Hey everyone


As you may be able to tell from the photos, I have finished a theoretical design for a deep cut edge turning dodecahedron or a "big chop" (gelatinbrain 1.4.3). The idea for this puzzle has been around for a long time, and I hate to say it, but it may just stay an idea. You may not be able to tell from the photos, but this puzzle is HUGE. The edge length for the dodecahedron used is 100mm. For reference, a dodecahedron of this size would stand roughly 9 inches tall, which is just absurd for a puzzle. It is far too large for numerous reasons(handling, friction, print costs etc.). The mechanism is riddled with potential problem areas, although there is only one that drive the puzzle to be this enormous size, which I will talk about in detail later.

The first photo shows the overall mechanism of the puzzle, which is just a standard "shell mech." This doesn't really show anything special, although it does highlight how strange some of the parts look. The cuts create some really odd non-symmetrical parts (which is a problem in itself).



This picture shows in detail the real problem with the puzzle, the so called "rails layer" for convenience to the viewer, I had made all similar parts the same color.


big chop rails layer



The rails layer on any deep cut puzzle made using the shell mech is the result of the "overlapping" of parts when going form the master version of the puzzle to the deep cut version. For example, master penultimate-->penultimate, master skewb-->skewb, or even a 3x3-->2x2. The rails layer that I am showing here is actually two identical rails layers on top of one another (this does not increase the part count) as to increase the stability of the puzzle by increasing the total amount of footing size(or the area where the parts can grip). The reason why this rails layer causes the puzzle to be so bloated is because of the orange colored parts. These parts (in the 100mm edge length version) are at the absolute limit of part size (excluding things like gigr's micro 3x3, those parts are no where near strong enough). As the edge length of the puzzle decreases so do the size of all the parts in it, and these parts cannot afford to be any smaller, resulting in this behemoth of a puzzle.

What I find to be very interesting is that on every deep cut puzzle made using the shells mechanism, parts always occur that are analogous to one another (below is a picture of a 24 cube rails mechanism, so that way it is easier to see what I am talking about). Part A hold onto part B, B holds on to C, etc. What makes the rails layer for the big chop such a challenge is the fact that you end up with decagonal symmetry for the part on the rails layer that hold all the rail parts in (pictured red). The decagonal symmetry is a result of the geometry of the edge turning dodecahedron and, as far as I know, is totally and hopelessly unavoidable when using the shells mechanism.


24 cube rails layer:





As far as I can tell the big chop is technically possible, but totally impractical and insane.

Now for the real reason I started this thread, I want to promote a discussion about alternate mechanisms to bring this puzzle to a reality. I (possibly more than anyone else) want this puzzle to come to life and am very eager to hear what you have to say. Please post any ideas/thoughts you have, and If you want to share a mechanism with me in private, don't hesitate to send me a pm.

P.S. a big Thanks to Drewseph who started the file I did all my work on. It was the base I built off of and I would not have had the sanity to do 100% of the work.

P.P.S. I wrote this at 2 in the morning so please excuse my grammar mistakes, I'm sure there are a lot.

If the cut can't be a deep cut, what is the deepest this cut can go an not make the puzzle impractical?

That's pretty crazy, Eric. Considering that this would be the mother of all deep-cut puzzles, I'd love to see a mechanism be pioneered and eventually work.

To give people some idea of what that problem section would look like in context of a shell:
http://www.jaapsch.net/puzzles/sphere.h ... gle=0,90,0

I remember talking to Bram about this a while back. He explained to me what the big chop was (you know, the OTHER deep cut puzzle that has only 180 degree rotations).
I looked at that setup on Jaap's Sphere App, and (almost) immediately said "Nope"

I am so not the right person to come up with something useful here, but is "fudging" something that could be used?

What do you think about partly using magnest and partly mechanism?

Do you think a master version would be 'more' possible?

I too would like to see this puzzle coming to life without having to use a 2-part box to hold it when turning.

As I know nothing of the subject, I'll ask questions: Is it possible for a 24 Cube to be made from a Helicopter Cube?

If you can, then what is the problem with making one from a Helicopter Dodecahedron?

The 24 cube IS made from a helicopter cube, just as the big chop is made from a helicopter dodecahedron. The problem is on a dodecahedron, the part number, and shell number required increases greatly.

While I am at it I think that the shells mechanism can be simplified a little bit to reduce some of the rails, I also think that some fudging can be done to get rid of some of those little pieces. For my Icosacopter design I originally had some smaller "floating" pieces similar to the ones here. I was basically able to make them as small as possible and then do a little fudging so it doesn't hurt the rest of the mechanism to simply not include those pieces

So how many pieces does i have with/without those pieces that need to be included?

Unless the mech somehow skips layers, it should have all the pieces described in this thread. So 2845.