Think Diagonally and Other Directions

Diagonal Twins by Yasuhiro Hashimoto produced by Mine
Note that this photo only shows the pieces as previously displayed by Mine

When the Diagonal Twins by Yasuriro-san was awarded the Puzzler's award AND a Jury honourable mention award at the IPP design competition last year, many of us waited with baited breath for Mine to complete his production run and post them out. It took him quite a while but we were all happy to wait to get hold of something truly special. I haven't had much time to play with it until fairly recently but have taken it to work a few times and let some colleagues loose on it.

There must be something quite compelling about such a simple puzzle because everyone I showed it to was unable to resist playing with it. Having 2 pairs of identical twin pieces made from lovely wood and a simple box with a slightly restricted opening makes it look like it should be an easy thing to solve. I watched everyone play and fail over many many attempts and was delighted by their frustration. Despite watching them play, I only had a little time to try myself. 

The puzzle is very reminiscent of the Pin Block Case by Hajime Katsumoto (produced by Eric Fuller) which I reviewed way back in 2018. It also has 4 pieces to be inserted into a simple cubic box through a restricted opening and requires a very beautiful sequence of moves to solve.

Pin Block Case by Hajime Katsumoto

Over the last week I have been working on this myself and trying my usual attempts outside the box. The pieces fit together in only a linmtied number of ways and so the issue is getting the conformation to go inside. This is much easier to talk about than actually do. I tried to be systematic and find an assembly that I would be able to disassemble through a limited opening and that is where I got stuck. There seem to be a lot of ways it should be possible but the curved sides of the opening prevent almost everything that i wanted to do. Damn! I really struggled. 

I even continued in desperation this morning to try and solve it. If I wasn't successful then I would have nothing interesting to write about for the blog. The pressure was on! Man! This one was tough. After about 1½ hours of muttering to myself (luckily Mrs S was elsewhere) I finally had my Aha! moment and the pieces finally slid home. I can now see why this won the prize - it is such a simple idea and yet so tremendously beautiful in its execution. I cannot show you the packed puzzle as it would give too much away but I have to agree with the Jury and all the puzzlers at last years IPP - it's amazing. If you get a chance to buy a copy or even just play with a copy then you should definitely jump at it. I will be bringing this and the Pin Block Case to work for a while to torture my friends with.

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Jigsaw P4z by Mine
Same photo as released by Mine himself so as not to give too much away

I also challenged my work colleagues with another lovely little simple design by Mine. This is a simple 4 piece jigsaw with a square framed tray to assemble them inside. It arrives with the Jigsaw already pre-assembled so what is the challenge? Take the puzzle pieces and assemble them so that all the nobbles and holes are paired but make it so that the puzzle cannot move in the tray. It's really not terribly tough but needs a little thought and leaves both beginners and experienced puzzlers with a satisfied Aha! moment when they work it out. Everyone I gave it to solved it in about 5-10 minutes and they were all very pleased with themselves. 

Thank you Mine, for the opportunity to play with these. I still have a whole bunch of extras that I haven't gotten around to yet. Most are tray type packing puzzles so I expect them to take me many years!

I Don't Understand The Difficulty!

Chiral 2&2 by Koichi Miura

Sigh! I have been working on this puzzle for since I got it in amongst a large batch from Mine way back in February 2021. Yes, that is 5 years! It has been in my work bag for the whole time and I would take it out to play with it at least once every week or two and even let colleagues play if they showed interest and could be trusted not to use force. It never got solved. It's a pretty simple challenge. There are 4 tetrominoes (2 pairs of chiral shapes) to be fitted into a 3x3x2 box through a diagonal opening in the top. There are no other holes or widening to be useful. It really shouldn't be that hard. 

It certainly should be clever because it won a Jury honourable mention at the 2021 IPP design competition. Usually puzzles that are incredibly tough don't do particularly well in the competition. It requires a solution to be beautiful or unusual or really clever. Despite the supposed lack of extreme difficulty, I just couldn't seem to solve it. I had tried what I thought was every possible move and every possible assembly and just failed every time.

Always easy to get 3 of the 4 pieces in!

Usually after a period of several months, I remove failed puzzles from my work bag and transfer them to the desk in my study or one of the various caches of unsolved toys around the house. But I hadn't done it with this one for several reasons. My study desk is now so completely covered in stuff I either haven't solved or haven't gotten around to putting away that I daren't add any more for fear of the whole leaning tower coming crashing down. The other puzzle stashes are starting to annoy the present wife (actually they started that about 3 years ago) and so I am trying not to clutter them up more. So, I kept on trying week in and week out.

Recently I have received some rather amazing complex toys and have been working on them:

Emerald Vault

Rune Lock

Two fabulously beautiful challenges from Dedwood crafts - I haven't managed to solve any of Dee's puzzles for a very long time. I don't know why - maybe I am rubbish at puzzles?

Gravity Box

I need my lunch

These fabulous challenges take a long time for someone as dim as me and so I need a few nice quick and easy puzzles to write about as well. In desperation with nothing to write about after I spent 7 hours writing the on-call rotas for our department, I decided to torture myself with something that I had failed on for 5 years. What could possibly go wrong?

As usual, start outside the box, make some shapes that will fit in and see whether they can be taken out piece by piece. There is a very specific set of requirements for the pieces to be removed. I was able to cut down the solution set quite quickly and found a few positions where 1 piece would easily be removed but a second would be impossible. I also (for the 100th time) found a nice arrangement where 2 pieces were removable. Now I needed to work out how I could get the remaining 2 into/out of the box. It was going to need rotations and they were going to be hard to find. There really isn't much room for manoeuvring once one piece is inside. Nothing seemed to work! I found a few nice possible rotational moves but either they wouldn't work when another piece was inside or they took me in the wrong direction. Aargh! I vaguely remember Derek (remember, he's the genius) mentioning to me that one of these puzzles from Mine required a coordinate motion. So I tried that and also got nowhere.

I spent yesterday evening muttering to myself and still failing. Aargh! This morning, I had a nice lie in and came downstairs nice and refreshed - ready to crush it and write up a wonderful review. Mrs S and I have got on board with this intermittent fasting thing and don't eat anything until about 1pm. She duly came into the kitchen for breakfast to find me with my head in my hands and muttering to dark oaths to myself and wishing I had some hair to tear out. As any good wife would, she laughed at me and said I was useless at puzzles and should give it all up. This made me sit up and drop a piece into the box where it sort of fell onto its side in a way that I hadn't thought would be possible.

OMG! By taunting me, she had forced me to find a new move! 

AHA!

Don't look if you don't want to see a spoiler - otherwise click on the button for a solved view.

Why had I failed for so long?

 

I had suddenly found a wonderful move that should have been perfectly obvious from the very beginning. It wasn't even that difficult a move but I had not been able to see it for all those years until a combination of desperation and ridicule made it possible. Maybe I need to get Mrs S to make fun of me more often? Maybe not!

Burrtools tells me that there are 10 possible assemblies of the pieces into the 3x3x2 shape but only 2 (mirror images) are possible solutions. I didn't use BT until after I had solved it.

I can see why it won the honourable mention. It is not actually that tough but is very clever and well hidden. I just love almost everything that Koichi-san designs. He's a genius too!

These come up for sale periodically on Puzzle Paradise and it's definitely worth getting hold of a copy.

Sometimes Burrtools Is A Godsend...

And Often Not!

P3C by Yasuhiro Hashimoto (produced by Mine)

Every 6 months or so, Mine offers up a bunch of puzzles that his Japanese friends design (many of them appeared in the IPP design competition). The P3C arrived and I set to work on it shortly after it arrived. Needless to say, I failed! Again and again and again! It got to the point that I put it in my work bag and would get it out every few weeks to try and yes, you guessed it, fail again! 

There's another one that shares that fate - the Turning Quarter Hole has been in my bag for 5 years and still not been solved! OMG! I received it in March 2022 and still not solved it. Maybe I need to give up this puzzling hobby?

Interestingly, these two puzzles share the same 6 tetromino pieces and same aim of packing them in a box that measure 24 voxels in volume but have different dimensions (the P3C has a box that is 2x3x4 and the  Turning Quarter Hole box measures 4x4x2 with all 4 corners blocked by diagonal walls. Obviously the entry holes are different and the latter puzzle has a top lid that is captive but can rotate freely. 

These two have accompanied for such a long time that I eventually got desperate with one of them and decided to let Burrtools do a comprehensive analysis for me. I was pretty certain that it would not be able to solve it for me. The box has a nice 2x2 hole in the top and there are two single voxel holes in the bottom. I did wonder whether the solution would be linear with pieces needing to drop through the holes to allow others to pass over the top. But... after nearly 2 years of trying I was fairly certain that the holes in the bottom were just finger holes to allow manipulation and that some kind of rotation might be needed. 

I duly entered the puzzle entirely into that wonderful programme by Andreas and, as expected, no solution popped out. It did give me all the possible ways that the 6 tetrominoes could be assembled in the box. "All" that was needed was to try them all out systematically and work out which could be disassembled a reasonable amount through the hole in the top until there was room for other pieces to achieve any required rotations. BT found that there were 28 possible assembles and I started at number one. It didn't take much to work out that all but 3 of them were absolutely impossible as solutions. After this, I tried to be systematic on them and skipped past the solution for several hours. It was right in front of me but I couldn't see it! Those holes are not just finger holes - once you realise that there are a whole lot more possible moves to think about. I had my Aha! moment and finally one of Mine's creations can be put away. Yes, Burrtools to the rescue yet again.

I am not going to show the final packed solution because that is not allowed with these puzzles from Mine. I don't think he has any left but I am sure that you could find the shapes and print your own if you were allowed a 3D printer in your house. Unlike me who daren't even think about it.

I still have the Turning Quarter Hole puzzle accompanying me everywhere and I don't think that BT will help. 

Actually, whilst I am focussing on Mine's puzzles that are always with me there is an even "simpler" design of Koichi Miura's produced by Mine, the Chiral 2&2 which has also completely stumped me because rotations are going to be needed and BT won't help me:

Chiral 2&2 by Koichi Miura

This one has just 4 tetrominoes to be placed in a 3x3x2 box - yes, there are 4 spare voxels free inside so it should be easy peasy - but not for me. I have had this one and gotten absolutely nowhere. Sigh!

Minima Imposter currently available from NothingYetDesigns

Finally, Tye Stahly sent me another Minima puzzle - this one, designed by Kyle Waszak and Ryan Sinatra, shares the 2x2x3 cavity of the usual Miinima box but has a slide on lid.  As soon as I tipped the pieces out, something didn't look right. I had to put my maths head on and calculate that 2x2x3 equals 12 voxels. Then I counted on the digits of two hands and then a foot (having taken my shoes and socks off) there were 12⅓ voxels on the pieces to be packed. Huh! Well, that's odd. Is there a hidden dimension or a portal to somewhere else? I quickly made two vital discoveries but they didn't seem to help with this puzzles at all. BT definitely wasn't going to help with this one! 

Damn you Tye! Is this another one that will be traveling with me for years to come? Sob!

If you want to try and succeed where I failed then it is still available from NothingYetDesigns.

Revitalised By An MPP!

Bicolor 1365 by Koichi Miura
Purchased from Mine

I've been in a bit of a puzzle slump recently. Too busy and too tired to really play with much. It's only been the constant pressure of the blog that has kept me working on solving stuff and often I find myself leaving it until I have just a day to go before publishing to start playing. I really need to cut down the amount I work. I'm getting too old for it - I discovered yesterday, to my horror, that I am older than Frank, Big Steve and Allard! Damn! I'm old! 😱

That's quite something!

I received a bunch of puzzles from Mine at the beginning of the year and have put them in my file of puzzles to be played with and just left them there. Part of the reason for not playing was the strange warping that happened to the lid of one of the puzzles which occurred between the time they were manufactured and the time they were sent/received. Whenever I looked at it, I just got a disappointed feeling. Mine had apologised to everyone and it is an unfortunate side effect of the use of two different woods side by side. 

Every time I looked at the pile I felt guilty and picked one or two from the Mine delivery up and played a little before failing and putting them back... Until last night and this morning when I had a sudden rush of something to the head!

Yesterday was the 55th MPP (at least that's what LCVX seems to mean even if it is completely invalid Roman Numerals). I managed to work my way through 1 or 2 burrs in the shape of locks and even some in the shape of a tetrahedron and also worked my way through 4 or 5 of the Karakuri Xmas presents which was fun. I really got quite badly stuck on the set of Demonticons and needed quite a lot of assistance. I really must buy them soon. One fun thing to watch was Big Steve and Amy working on the Bicolor 1365 from Mine. It's a brilliant design by Koichi Miura which looks to be deceptively difficult based on the two of them working on it for ages and bickering at each other like an old married couple! The whole group of us got a LOT of entertainment watching them fail for a VERY long time. Needless to say, this motivated me to get my copy out when I got home and whilst watching TV that evening with the present Mrs S, I experimented and saw just how difficult it was.

Instructions

When the lid is placed, the colours will not match

I am not allowed to show the pieces but it is interesting because it consists of a box with a 3x3x2 voxel cavity with a fixed cubic on the base of the box and another fixed on the lid. The pieces completely fill the cavity and consist of 3 full voxel pieces and 4 more made with ½ voxels. It arrives in a solved state but in the "warmup state". I tipped the pieces out and examined them - the split pieces all fit together nicely to make whole ones and obviously I walked right into Koichi-san's trap! I spent the whole evening managing to create quite a few of the 1365 possible assemblies.

Every single time, I managed to fail to create the one single correct assembly that would allow the lid to be placed the correct way around. Finally, it was bed time and I put it down with relief. Sunday morning bright and groggy, I went back to work on it. Doing the same thing over and over again like Steve and Amy eventually got frustrating and I had a little think©. That hurt quite a bit and after recovering from the shock, I had a little fiddle with the split pieces to see how else they could be assembled and how they might then interact with the whole pieces. At some point after a couple of hours there was a really big Aha! moment and I tried something new. It wasn't quite right but I could tell I was nearly there. All I needed to do was fiddle a little bit and yessssss!

Take my word for it - the pieces are inside!
It's still a shame about the warping but the puzzle is great!

Having actually solved something thanks to the MPP, I figured that I should keep going whilst I was on a roll:

Bram's Hinged Cube
3D printed by Allard

The whole world is aware of Bram Cohen for a number of reasons. We all know of him as a brilliant puzzler and designer. Very recently he showed off a new design and allowed the puzzle to be made freely available by releasing the stl files for printing. When I arrived in Birmingham, there were a bunch of these available for grabs and I couldn't resist a lovely lilac copy (maybe Mrs S might like it? Whack! Ouch! That will be a no then.)

As you can see, each cube has a hinge on it attaching it to an adjacent cube and 3 of them are attached to 2 cubes. 2 of the cubes have a "blocker" on them which will interfere with adjacent hinges. The aim is to manipulate the hinges to assemble a 2x2x2 cube in such a way that the blockers don't clash. The rotation of the chains of cubies cause them to interfere with each other and there should be no force involved. This looked so good that I picked up another couple of copies to give away to colleagues at work. 

Two more copies to give away.
Notice that there're quite a few flat shapes to be made.

Playing with this is fascinating and reminiscent of the old Rubik's snake. It gets blocked very quickly and the temptation is to force pieces to move past each other. Resist that temptation as you don't want to pop a hinge. It is a fun thing to play with - several times I created a 2x2x2 cube with just one cube out of place and, after a good hour, I got an almost there solution but we all know that "almost" is not solved.

Blocked from achieving the solution

Finally after a couple of hours I had an Aha! moment and could see the correct cube assembly but getting the pieces into place was a big challenge. It required me to undo almost the whole thing to move pieces out of the way before trying again in a different order:

Bram is a genius!
Thanks to Allard for making me a copy.

Undoing it is also a bit of a challenge - I could not for the life of me work out how to return to the starting flat shape. To my shame it took me a good 20 minutes! And now I can't repeat the solve which means I didn't understand it at all - time to keep 

I even managed to solve an easier puzzle that Allard gave away:

Stella Octangular Puzzle

I couldn't resist this - straight away I realised that this was a version of the Triangular star puzzle. In fact, as far as I can tell it is identical and creates a very pleasing shape when assembled

Very pleasing - Just pull opposite vertices to disassemble

I am now busy working on a copy of Stewart Coffin's Diamonds puzzle (STC #269) which looks fairly simple but so far the full assembly has eluded me:

Diamonds (STC #269) printed by Allard

As you can see, attending an MPP has revitalised my puzzling - it's not an entirely solitary pastime this. Playing with friends and watching others struggle is very good for the motivation.

Don't tell Mrs S but I might have acquired a new lock whilst there. Andrew Coles is about to release a new lock to the world. The Clutch Lock is beautifully made and so far, I have done one thing and discovered why it has that name. It might be years before I make the next discovery!

Clutch Lock by AC puzzles

Looking forward to the next MPP in May - it may be the next time I solve anything! 😱

Going Solo on the Stairs?

Solo in basket by Koichi Miura
Beautifully made by Mine

I had not expected to have two weeks of tributes to Koichi-san but it worked out that 4 of the 5 puzzles that I purchased from Mine's store were designs by him and they turned out to be just what I needed in times of stress and burnout. For some reason I seem to be working pretty much 6 days a week for a 3 month period and this is having a bit of a toll on my general energy levels and my puzzle solving abilities. I am just too damned tired to solve much! I know, I am the one that writes the rotas at work and should be more in control but I work one weekend day in trauma and another writing rotas and another in a non-NHS hospital and the diary fills up very quickly without realising what I have done. 

Luckily for me the puzzles from Mine are just perfect for an overworked bloke! The next challenge I picked up after the delights from last week was the Solo in basket. The reason for the name is pretty obvious from the photo and I thought that this has only 4 nice simple tetrominoes and can't possibly be terribly difficult to fit them into the 3x3x2 basket - there will obviously be 2 empty voxels somewhere inside. The entry to the basket is divided into thirds by the handle which will obviously severely limit the positioning. The bottom of that handle is elevated by a couple of mm which is absolutely critical for the solution even if I did not realise that at first.

Picking up the pieces and experimenting with the different way to create the final shape reveals that the options are very limited. There are, in fact, 11 ways to fit the pieces in that shape but the vast majority of them can be discounted due to the fact that more than one of them are oriented flat or perpendicular to the entry slots and that achieving that is impossible. I played for a while and realised that this was not as straightforward as I had initially thought. I should have realised it would be a decent challenge because Mine never chooses puzzles that are simple. He is a master of seeing the wonder in something special. Believe me...this is special!

I spent about 45 minutes failing to assemble any of the shapes I had found inside the basket and had to think© which in my weakened state was not easy. I eventually realised that a special sequence of moves might be needed and attempted it with several of the pieces and it seemed to be blocked. That is, until I tried something rather non-intuitive. I had the most beautiful Aha! moment at this point and got to understand the incredible design and the beautiful precision of the manufacture. If the shapes of the pieces or basket were even a mm out then this would not be possible but it's perfect and beautiful:

No spoilers here - Solo is now packed

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Stairs Posting - also by Koichi-san

I cannot show the complete puzzle here for fear of allowing people to make a copy without permission. The 4th puzzle in my delivery was Stair posting - it also has 4 planar pieces to be fitted inside a 3x3x2 box but this time with no spare empty voxels. The pieces need to be posted through the entry slot like a letter through a postbox. The puzzle is named because all of the pieces look like stairs if placed on their edge. Imagine all the different ways you could make stairs using a triomino, tetromino, pentomino and a hexomino and hence posting of stairs.

It arrives with one piece poking out the letterbox and an invitation to rethink it. I found this one just lovely. It is not difficult and the design has been perfectly created to allow manipulation of the pieces through the entry hole and the convenient hole in the top and once finished there are no gaps. It took me only 10 minutes to work it out but has been much more challenging for work colleagues who are not used to this type of thinking. It is perfect for the newbie or your friends.

The stairs have all been posted!

Thank you Koichi-san and Mine-san - you have really helped me keep my sanity during the last 2 weeks of overwork.

Koichi-san Bamboozles Some Operating Theatre Staff

Latest arrivals from Mineyuki Uyematsu

Mine has been very very busy this year. Life got in the way for him and the proposed puzzle manufacture took much longer than he had hoped but everyone was patient and understood that sometimes puzzles have to wait. I had requested this set (there could have been a whole lot more but I was frightened of the Whack! Ouch!) and they arrived during the week - in fact I was sitting at home in a MS Teams meeting when the delivery man arrived and I had to sneak out of the meeting to answer the door. One colleague in the meeting let out a big smile when he saw me arrive back on screen carrying a nice big box from "the foreign" - he knew about my habit/hobby/obsession. Actually, everyone I have Teams meetings with knows about my hobby because I have set my background as the first few puzzle shelves of my study. I have been asked by quite a lot of people what they are. After the meeting I eagerly unpacked and found these Japanese beauties inside - I couldn't even remember what I had ordered.

I set to work that evening on a couple of them which I will present now. The first one I tried was the rather fascinating looking Perfect Entrance by Koichi Miura (all of them have been made by Mine). I am very careful with puzzles from Mine not to show off any more details of a puzzle than he shows off on his Facebook page. 

Perfect Entrance - 2 pairs of pieces

More interesting than a knee replacement!

This wonderful 4 piece packing puzzle made from acrylic is truly beautiful. It also was an entry in the 2024 IPP design competition and won a "Top 10 vote getter prize". When I showed off my latest arrivals on Facebook, the genius did tell me that he thought that it was a brilliant puzzle and he really should know! To me, it has just the right difficulty level for any puzzler of any experience and will keep you working for just the right amount of time until you triumph having had 2 or 3 simply lovely Aha! moments.

 The 2 pairs of C-shaped pieces have interesting diagonal ends to them which must be significant. They all have the same outer dimensions which perfectly fits through the rectangular hole in the top of the case. It is very easy to fit 2 in side by side and then a third on the top layer but still within the case but after that, the 4th piece cannot fit under the lip of the top. Hmm! Maybe rotations inside are needed and off you go to try that for a bit. 

Having had no rotational luck, it is time to think like a burr and maybe the pieces move around each other inside the box to make space for the final piece to go in (this is very reminiscent of the challenges from Osanori-san and Alexander-san. Whilst attempting these moves you might find a little Aha! moment when the odd shapes suddenly make sense. Even having found the first of the Aha! moments, you will still be unable to proceed until you have been forced to think©! When I finally packed them all in, I had a huge grin on my face - I can visualise the puzzlers in the competition room with the same grin - no wonder it got so many votes! Of course I am not going to show you the solved puzzle!

The 2 miscreants in the photo above spent a good hour trying and in the end gave up and asked me to show them the solution - they too had big grins when the saw how clever it was. I gave this to several of the other operating theatre staff and they also failed but loved being shown how it was solved. It is truly wonderful!

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3Lx2 as it arrived

Having had lots of fun with that one from Koichi-san, I couldn't resist the 3Lx2 also designed by him. It consists of another 2 layer box but with a lid that slides from side to side. The aim, as you'd expect from the name is to pack the 6 pieces (3 of each different type of L shape) into the box. When it arrived, it was difficult to see how it was special because one of the pieces is protruding into a third layer and obstructing the movement of the lid. Once you have turned out the pieces (not easy without a few rotations and perfect alignment) then you get to see why the puzzle is so-named:

2 different sets of L's

I had not solved it but took it to work with me in the hope that I might have a little downtime to play. I felt brave and handed it to the 2 miscreants above to play with before I had even tried. They spent an hour on it intermittently whilst also helping me with a revision knee replacement and they were forced to give in. They handed it to me during the case and wanted to watch my approach to it. The pressure was on as they didn't want to see me fail and I did still had to concentrate on the case. 

Obviously, it is necessary to explore how the pieces can move inside the case. There are 2 layers for the pieces under the lid and yet again, once a few pieces are inside, it is difficult to get any more in. It is vital to move them around inside and make space for the appropriate diagonal insertions. I had a pretty good idea of how it was necessary to proceed and created a few possible assemblies outside the box (just as the boys had done) but then I did something they had not thought to do. I mimicked a disassembly from the shape I had created to see whether it might be possible to insert the pieces that way and also what order was required. This was new to them. I did work out that there was going to have to be a few nice sliding and rotational moves to make it happen and in just 10 minutes I packed them in:

No spoilers here!

Needless to say, they were all very impressed with my prowess. If only I could say that the present wife was quite so impressed with my prowess! Alas, that will probably never happen.

Thank you Koichi-san and Mine-san - fantastic puzzles.