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.