Sunday 28 April 2019

I Grille(d) This Cube...

And Found It Wanting!
Grilles II cube - looks horrific
2 types of turns
Over a year ago, the Grilles II cube was released by MF8 (I have no idea what happened to the Grilles I cube) and I bought it without even a thought! It looked hugely complex, was much more interesting than a standard Rubik type puzzle and I knew that with its' unusual turning it would be a fascinating challenge...And then I turned it a bit! GULP!

4x4 curvy dino
This stunning puzzle is effectively a 3x3 Rubik cube i.e. face turning combined with a variant of a version of a 4x4 corner turning cube, the 4x4 curvy Dino cube which I enjoyed enormously, having reviewed it not long ago here. The 4x4 Curvy dino was a great fun puzzle and pleasant to play with - it had a nice challenge to it but was not impossibly difficult and was even soothing. Any puzzler interested in Twisties should have bought it and would be able to solve it without too much difficulty. The addition of face turning moves to the challenge looked like it would add some extra work but hopefully not too impossible for a neophyte like me. I turned it a few times to see how the pieces might interact and then threw caution to the wind and scrambled the bugger! Oh boy - that produced something quite horrific!

Houston! We might have a problem!
The scrambling process is quite a long one and takes a bit of an effort to work to separate as many adjacent colours as possible. It really does get very scrambled but straight away you come across a problem with this puzzle - the pieces catch on each other very easily - especially the face turns. Initially, I thought that it was occurring because I had not properly aligned the corner turns before carrying out the face turns - it is quite possible to keep the corners aligned because the whole puzzle is very "squishy". I started working on it over a table so that I could flatten it out properly before carrying out a face turn but at this point, it became clear that the problem was not just because of malalignment. Something inside would catch the face turns almost every single time.

It was not long before the air around me went blue:

That's a whole lotta pieces!
I had an explosion over a very deeply sleeping cat who was not at all impressed at 20 or 30 bits of plastic raining down on him! A small pop very rapidly ends up as a very major explosion. Then, having been scrambled, it is not just a matter of stuffing the pieces back in any old place - that is a way to end up with an impossibly assembled puzzle - a full disassembly is required. On several occasions, I actually lost one or two of the pieces in the crevices of my chair and thought I had a defunct puzzle.

I could not find any plastic flashing as the cause of the catching and explosion - rather I think that the corner pieces (which are assembled from 3 separate pieces) are not tightly held together and so anything which puts any stress on one side or other can make them fly apart and then the forces holding the rest of the pieces have been removed...BANG! The reassembly is not a trivial event either! This puzzle is extremely unstable until more or less the last piece has been inserted. If you attempt this then you WILL require tape - I find that light surgical tape is perfect.

Build it up section by section and tape them in place
Having successfully assembled the puzzle, it was time to scramble again...BANG! Oh Lord! Not again! A second reassembly and I put it aside for a few months to calm my nerves!

It remained stored as a potential puzzle to try for many months and I picked it up again a few months ago and scrambled it. As with a lot of puzzles which appear to be a more complex version of something already in existence, my aim would be to reduce it to one of the base puzzles - in this case, I would attempt to reduce it to a 3x3 which I could then solve as a standard Rubik cube.

As with most corner turning puzzles that are not really deep cut (like the Skewb), movement of the pieces around the edges is fairly trivial and usually can be done with the ever-helpful up, up, down, down combination. I started pairing up the larger parts of the edges - that would be pieces like the red and blue piece at the bottom of the picture above. This was very similar to solving a standard 4x4 - make the edges and then store them out of the way - easy until you have just 2 or 3 left but definitely a fun challenge. At this point I found I had a surprise:

All double edges are paired up and placed
BUT the red-yellow and opposite orange-yellow pairs need to swap
I had 2 pairs of edges that needed to be swapped. Nothing I tried would work - time to THINK©...It took me a week to sort that one out! It was time to solve the centres of the edges - using my standard up, up, down, down moves with setups too and all was going well. Or so I thought...

All the edges are done but I had 2 swapped
Again, this stumped me for a week! THINK© again! This time I had to use the up, up, down, down rather creatively and several times. Not on the small edge pieces but to reverse the entire direction of an edge. It is a standard series of moves in the "Ultimate solution" and rather fun to have to use it here. Finally, just the outer edges to move about and BINGO!

The puzzle was solved after just 10-11 months! Most of the time it was sitting on a shelf or in my bag waiting to be solved but a fair bit of time was thinking©. Time to try again and Boom! I had pieces again. Laborious reassemble and after calming my nerves TRY AGAIN. Solved it! Yay! A third time and oooooh! What is this? Another unexpected event - a single corner turned:

Nice corner parity!
Luckily this was not terribly hard to fix - if you remember the Dreidel cube (ecstatically reviewed here) then a similar event can occur with that and the solution is the same - it's not tough - just needs more thought.

I usually try to solve a puzzle 8-10 times to prove to myself that I have mastered all nuances of it but this I probably only managed 5-6 solves of this - it just kept exploding on me! For this reason, I have to come to the conclusion that this is a very nice puzzling challenge but definitely NOT one I can recommend to most puzzlers. It is just too unstable and the reassembly is neither trivial nor fun. If you are a collector then go for it and just be very careful when you play with it - you will enjoy the challenge of the solve but if it catches in any way at all then just stop and backtrack and realign before trying the move again. I am pleased that I own this puzzle and have solved it but it is going back in storage and is unlikely to ever be scrambled again.

Part way through my solution of this one, I did think there was a remarkable similarity to a puzzle I bought from Chewie's Custom Stickers, the Corona cube:

Corona Cube
As you can see it is an edge turner and a corner turner - only one level of corner cut and the depth is different - it was fun to scramble this one and see how it compared:

Very similar cuts but not quite the same - how would the solve be?
The puzzle was FDM printed and took quite a bit of effort to move and hurt my hands a bit in the process but at least there was no popping.

A nice challenge
The Corona cube was easier to solve with fewer pieces but very stable. After a couple of solves, I put it away as my hands were killing me. I still have a few more twisties awaiting my attention but they scare me to death! Plus after the Grilles II cube, we are all exhausted!

Wow! Dad! I need to lie down after solving that one!