Gravitational Burr

A Burr That’s Also a Maze

Gravitational Burr by Junichi Yananose
Gorgeous wood!

Well, what a way to start the year! First, I start on the amazing PicoLock and now I have a stunning and fun chunk of wood sent all the way from t'other (getting in touch with my inner Yorkshireman) side of the world.

This beauty has been made from a rather gorgeously grained American Black Walnut and Juno has mixed and matched the light grained pieces with the dark to make something arrestingly beautiful (I am a sucker for lovely wood) and the fact that it is a fabulously tactile 117mm across in each direction makes for a really nice thing to play with. The only downside is that my Juno puzzle collection is currently stuffed into 2 shelves of my Billy bookcases and this (plus the equally stunning Dual Meanders Box I also received) will now no longer fit in that space and I will need another reconfiguration.

Looking at it, you would think: "so what! It's just another 6 piece burr. Surely everything interesting has been done with this type of puzzle?" You might be right about that as I have multiple burr sets and am always on the lookout for more but this is NOT "just" a 6 piece burr. Juno has added a ball bearing inside and a track for it - therefore it is a 7 piece burr and the seventh piece needs to move around inside to allow the other 6 to move.

In fact, it is even more amazing than that. It is actually a level one 6 piece burr with a solid key piece which Juno has made into a level 2 one by having a tiny locking move that needs to be pushed to allow the key piece to slide. The locking mechanism is held firm by a pair of magnets. Once the key piece is unlocked then the first movements are possible and it quickly becomes clear where the name Gravitational burr" came from. You cannot initially see the ball bearing but you know it is there and the only way to manipulate it is to rock the puzzle side to side or turn it over and over. It is clear when the bearing has moved because you can hear it click to a new position. It is only after 4 moves that you can actually see the ball bearing and at this point a small part of the track/maze that it is in can be seen.

4 Moves in and the BB with some maze is revealed

Having found the bearing, I return to the beginning and try it again - it is weirdly satisfying just rolling the ball around and controlling where it goes by holding the key piece tight and clamping the ball in place and not allowing it to roll or fall until I was ready. I found a choice at the 5th move and I carried on deeper into the maze. After a few more moves I lost my courage and returned to the beginning again...except I couldn't get back to the beginning! GULP! Lost already? I knew that I was in good company because Goetz had got himself into the same difficulty. It was a little early for a full on panic and I just wiggled it about in every direction I could whilst manipulating the movable piece and, after a rather fraught 10 minutes, it was back at the beginning again. Phew! I was unable to play with this whilst Mrs S was around. She often takes the piss out of me for listening to puzzles and she very rarely will sit in silence - there is always radio or music or TV on around her and if it's too loud or too distracting then I cannot tell where the bearing is going.

I carried on with my exploration and found another pathway and all of a sudden my ball bearing was peeking out at me in a different part of the maze on a new section of the puzzle. How on earth did I get there? Back-tracking was really hard as I hadn't been really paying attention to orientation as well as piece position and I must have missed an opening. It took me a whole evening to return to the start.

Time to think©! Ouch! I could see that this was going to be rather complex and maybe I was going to have to draw a maze pathway. I started off doing just that and quickly came to the conclusion that my mapping skills weren't going to work. The problem for me and the fun part of this puzzle is that it is not just a burr...it is a maze and to make it extra fun it was a dynamic maze because the pathways moved with the key piece and parts that are blocked become available to explore only at certain positions. On top of this, the bearing needs to be moved by gravity making it impossible to randomly find your way through. I would go as far as to say that randomly exploring will get you into trouble as you will almost certainly get lost and then be in trouble.

Oh, the think©ing hurt me bad this time. I suspect that designing a hidden maze inside a burr using Burrtools might not be that difficult for an expert but that would almost certainly lead to a puzzle that required a lot of random moves and luck to get through - it would not be a good puzzle. Here Juno shows his true genius - with the Gravitational burr, Juno had designed the maze in such a way that once the initial confusion of manipulating the bearing and it popping up in odd places has been overcome, then the think©ing makes you realise that he is showing you different bits of the maze as you go. First you see the top of the key piece, then you see the sides of the key piece and later, a bit by surprise, you get a peek inside the body of the burr and see pathways on the fixed walls of the cavity. Each time you see a bit more it opens up a possible section for use. 

In the end, I actually deliberately worked my way through the pathway section by section until all of a sudden the key piece is in a very extended position to allow the extraction of other parts and full disassembly of the burr. Again, the genius of Juno is shown by the presence of a magnet which holds the ball bearing in place so that it doesn't fall out and get lost in the furniture or swallowed by a cat. In retrospect, I realised that magnet also held the bearing in place at the start of the puzzle - there is no rattle if you listen to the closed puzzle.

All 6 (7) pieces and Juno's stamp is revealed.

Once the puzzle is in pieces then the true genius is on show and you can look at the complexity of the pathway. Not really a spoiler but if you don't want to see the key piece detail then don't click the show hide.

Only half the key paths shown

Now it was time for reassembly. Juno has provided a quick assembly method which doesn't use the maze at all - there is a big cavity in one of the pieces where you can store the bearing and just assemble the 6 piece burr without it.

Ball in the hole and then assemble the burr for a level 2 puzzle

As usual, I had not paid attention properly to the positioning of the pieces and which order they came out in. Have I told you before that I am truly awful at assembly puzzles? To my eternal shame, it took me several hours to reassemble the burr without using the maze. Blush! 

Once I had worked out the burr assembly I was then able to deliberately work out my sequence of moves whilst able to see inside the puzzle and plan out the true reassembly. It took me about an hour to work it out and be certain of the sequence and orientation. Such fun even when you can see everything in place.

This puzzle is a masterpiece! It looks gorgeous, it looks simple and has layer upon layer of complexity and is definitely not solved by chance. It requires initial blind exploration followed by a reveal or 2 or 3 and then definite planning of your moves. Finally the reassembly is not just a simple backtrack - I wanted to truly understand it in its' entirety and that took some time and a lot of fun. Thank you Juno!

The Dual Meanders Box is waiting for me and after just a tiny bit of exploration, I have to say that it frightens me a lot - there are 506 moves to open it!

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Are you a Brass monkey fan? You should be! The BM puzzles are amazing. The 6th Brass monkey burr has just gone up for preorder/early bird sale! The previous 5 were amazing and this is set to be the very best yet. Go buy it now.

Brass Monkey 6 preorder information