Sunday 27 May 2018

The Heat is On! Some Surprisingly Difficult Puzzles.

Radiator I
I have had very little puzzling time the last few weeks despite having some annual leave! DIY (and the clear up after it) plus a return to a busy week at work have prevented much puzzling recently. So the heat was on for me to find something to blog about. A few evenings ago I decided to pick up a couple of the wire disentanglement puzzles that I received from Aaron Wang. This bunch are particularly complex and have made me pause a little before getting the courage to have a go. If you are keen to try some of Aaron's puzzles then many fabulous examples are currently for sale on Puzzle Paradise now (all are fabulous puzzles but I can particularly recommend the Lucky Lantern and the Libra twins). When Aaron showed off his latest productions I couldn't resist and bought all the ones that I didn't have and they have been sitting waiting for me for a while. I have been playing with one for a week or so now and recently this one dropped into my lap for evening play. Luckily for me the Whack! Ouch! situation is not too bad because this one is not jingly.

It is called Radiator for good reason...not only does it look like one, but it also laid the heat on as I tried to solve it. This is the first (and easiest of 3) which I feel I have to master before I attempt the silly ones:

Radiator II
Radiator III
I had been expecting these to be N-ary puzzles and spent a frustrating 5 minutes playing with Radiator I and trying to find a repeating sequence. Eventually, I realised that this one was a "simple" disentanglement. All I needed to do was unloop the string and ball. "Simple"? Maybe for a genius like Aaron but not for me. I realised the first evening what was sort of required but kept getting stuck with the string very badly looped up around the helices of the radiator. The string seems to be only just long enough to allow this to be solved which is a help as well as a hindrance. It is helpful because you can tell that if you are rapidly running out of string and manoeuvre room then you must have attempted something wrong. But the hindrance is that you have to position everything just right to allow yourself the space to solve it. I am very grateful that Aaron now uses the lobster claw clips to allow easy reset of these puzzles if you get in a mess. If that was not the case then these would become impossible knots quite quickly.

After my second evening of play, I had my Aha! moment and realised what was needed to remove the string. After I had convinced the cat on my lap not to eat the string or play with the wooden ball, I delightedly held up the pieces to show them off to Mrs S (she showed not the slightest bit of interest or encouragement). The solution to Radiator I is very logical and needs just a bit of investigation and then some proper logical thought (not something I am particularly good at):

Beautiful - a nice start to the set
As usual, I attempt the reversal of the solve and get stuck. The reassembly is another nice logical puzzle and should be the reverse of the disassembly but due to the complexity of the main piece, I struggle to visualise what is needed. I found myself getting half way there and as I continued it would magically reverse itself and fall apart! The reassembly took me over an hour! I love this puzzle - very clever idea and just the right level of complexity. Aaron has labelled it level 10+ but I think it is probably a Level 9 - the next ones will be MUCH harder!

Mobius Ring
The Mobius ring is slightly different from the others in that it arrived in a box and also arrived incorrectly assembled (different to the picture on the front). The incorrect assembly was rectified after a quick email question and here is what we are trying to disassemble. When I saw this one in a picture from Aaron it looked very familiar and I asked a question or two. After a single reply, I knew that I had to buy it because it took a couple of my older puzzles and raised the complexity to new heights. This REALLY turned the heat up! A long time ago (January 2017) the Puzzlemad foreign correspondent, Mike Desulets, reviewed the Russian heart puzzle by Jean-Claude Constantin and later I reviewed the Diskette puzzle - both have similar mechanisms to the solution.

Russian Heart
As you can see, they have the common feature of a double intertwined loop of wire with the string loop straddling both parts. The solution is very satisfying and you should all run out to Tomas Linden's Sloyd store to buy the Russian heart to experience the lovely Aha! moment. The Mobius Ring takes that same basic premise and adds an extra separate mobile ring of wire across the puzzle to add a whole lot of extra difficulty.

Having enjoyed the other two puzzles so much last year, I picked up the Mobius Ring first and very rapidly realised that I was in trouble. That damned extra ring makes a huge difference. It really gets in the way. I played with this every evening for a week and was very thankful for the lobster claw release mechanism. Finally, after a week of work, I had my two pieces:

OMG! That was VERY difficult!
So far I have not managed to reassemble it from scratch. In fact, despite having disassembled it 3 or 4 times, I can only do so whilst generating a bit of a tangle in the process which eventually undoes itself at the end. I cannot claim to fully understand the solution yet and plan to keep playing with it until I do!

Soma Tube
Finally, I have to end with another surprisingly tough puzzle! Except I really should not have been surprised! I have previously extolled the incredible brilliance of Laszlo Kmolnar - his packing puzzle designs have truly delighted me (even as someone who is notoriously bad at packing puzzles). When the Published professor of wood, Brian Menold, released his latest puzzles, I could not miss the Soma tube designed by Laszlo. My copy was made from Bolivian Rosewood and Maple (with an acrylic lid). Yes, it is JUST a Soma cube (which I proved to myself by taking about ½ an hour to assemble). I have said before that every puzzler should own a Soma cube and I stand by that - now I have two.

With this version, the aim is to assemble a cuboid (with a corner missing) which is actually quite a simple thing to do. My Burrtools file tells me that there are 1520 ways to make the correct shape but there is only one way to assemble the shape within a box through a T shaped hole in the top. Laszlo, you are a truly evil genius! I sat down at our dining table with this and spent the best part of a day working on it (moving a little periodically to prevent pressure sores!) I have to admit that it took me 2 days of effort before I found the solution! The Soma cube is relatively easy and all the other shapes that can be made are a nice diversion. The Soma tube is a surprisingly VERY tough variant which nearly broke me. It is sitting next to me assembled and I am hesitant to take it apart again - I think I will put it on display in the solved state!

My goodness! That was tremendously tough!
Now after those very difficult puzzles I really need to find something easier to work on for a rest. Maybe the next 2 Radiator puzzles? Maybe the latest twisties I bought are the right difficulty level??? Or maybe not.....

Sunday 20 May 2018

Is it Easy? Hell No!

The MF8 Son-mum cube
This week has been my first annual leave after my operation in November. I think that leaving it 5 months without having any time off is too long! I was all set for a rest but it was not to be. "We" had been discussing the terrible state of my study for a while and "we" had decided that enough was enough and it was time to do something about it! With visions of a huge bonfire in my garden, with a slight tremor in my voice, I asked what she intended as a solution? Ikea had opened a store in Sheffield last year and Mrs S had decided that one of our spare rooms could be used for puzzle display. Yay!!!

You can see why she was upset!
The small stretch of visible desk is to allow the cats to jump down from the windowsill.
The weekend before my annual leave we had a trip to the shop and navigated hundreds of screaming children before I discovered to my horror that Ikea is also known as "storage central"! We duly ordered some Billy bookcases with doors and extra glass shelves to be delivered (they would never fit in my Mini) and much to my disgust, she homed in on the chests of drawers, other items called Skubs and various items of storage. Another 6 chests were added to the delivery along with assorted other stuff and the following day a delivery occurred (yes, on a Sunday). The garage was even more of a mess after that!

That's a whole lotta flatpack!
My week then began with a DIY frenzy - chores first and then the assembly began! Firstly, as the title of the post says, I thought that it was going to be easy but, as usual, I was wrong! Each of the bookcases weighs the same as me and needed to be brought from the garage into the house down a long path! After nearly killing myself I invested in a sack trolley which helped. I have always had great respect for craftsmen and people who do physical work for a living! After 3 days of lugging stuff around and assembly, I was sore all over and towards the end, if I dropped anything it was going to have to stay on the floor because I couldn't bend down to pick it up again! The construction was not challenging but yet again I was reminded why buying a house from Barrett homes was a bad decision...the floors are horrifically uneven! They were all over the place leading to a major challenge getting everything lined up and level. It took nearly 3 days but I finally had a secondary puzzle cave. Time for toys to be placed inside. I started with the dining room...those toys which she found particularly annoying even if they are my most beautiful:

All nice and level!
Some of my most prized beauties go in first.
After the puzzle cabinets were constructed it was on to the rest of her storage purchases. As a result, the desk is still a mess and I am about to go back to work! My physical fitness and strength have, however, improved a lot!

Back to the puzzling! Not only was the DIY much harder than I expected, but the puzzle for this week was also MUCH tougher than I first thought. At the top of the post is the Son-mum cube made by MF8. The original design was by Mike Armbrust as the Shallow Mixup Cube. My copy was purchased from the HKNowstore (it is also available in N America from Puzzlemaster). I couldn't resist it because my experiences over the last couple of years with various Mixup cubes has been really good - they are amongst my favourite twisty puzzles.

As with the other Mixup puzzles they are special because of their ability to have the centre row and columns turn 45º and yet still allow the other faces to turn. This allows edges and centres to be interchanged which becomes quite confusing and also allows some wild shapeshifting.

Just 2 turns made.
As you can see from the picture above, this particular puzzle has the centres split into a 9 segment grid and all the segments can be split up leading to a very interesting variant on the 3x3 Rubik cube:

What have I done?
The first attempt was fun! I quickly managed to return it to cube shape and found the bandaging to be fairly easy to get past. After that, a straightforward hunt to recreate the centres also proved to be a very easy challenge once I had seen the secret of moving pieces about. No algorithms were required at all! Just very simple intuitive moves. Having recreated the centres and it was just a quick 3x3 solve and I was done! Fantastic! It had only taken me about an hour for that first solve - easy peasy!

Oh boy! That first solve had lulled me into a false sense of security. I did it again to make sure that it hadn't been a fluke...let's just say that it HAD been a fluke! My next attempt left me with a parity i.e. a position that is otherwise impossible in a standard 3x3 due to the reduction process:

A single flipped edge is not usually possible.
Time to engage the little grey cells (the few that haven't been pickled in gin yet). I recalled the original Mixup cube and after about half an hour of fiddling about (one day I will start to take notes on my puzzle solution methods so that I remember techniques used in the past). Eventually, I worked out a nice simple set of moves (hardly complex enough to be called an algorithm) which fixed the flipped edge, then another 3x3 solution and it was done - easy peasy? A little less so but not too bad. Not being very bright is a major shortcoming for me! I should have stopped there but no...I had to do it again.

I hit a brick wall! I seemed to be completely unable to return it to cube shape! The outer centre pieces were not lying flat and for some reason, there were only 6 of them sticking out. Had there been 8 then I could have lined them up and done an equatorial ¼ turn and had everything flat again with just the edges and very centres to swap. But with 6 of these pieces sticking out, I could not simply flatten them. I began to sweat and mutter under my breath! Again and again and again I failed! Suddenly after a couple of hours...aha! I now knew how to create and move them about. Still no algorithms needed...just fiddling about until things were right. The rest of the solution progressed without any parities and I breathed a sigh of relief!

Stupid boy! Did it again didn't you? These things are like an itch for me...I just have to scratch. The next scramble was a struggle yet again to return to cube shape but I managed it after a few minutes. Suddenly I thought to myself, "You've cracked it. You're a genius!" Wrong! I sat back in horror when I saw this:

Just 2 corners top swapped
Equivalent to 2 opposite edges swapped
These 2 pictures are an equivalent parity...both are impossible in a standard 3x3. It is usually impossible to have 2 corners or 2 edges swapped. This parity occurred for the first time and caught me by surprise - I had no idea such a thing was possible.

I was stumped! I thought that it must have been either due to the centres being recreated the wrong way or possibly due to the whole equator having ALL the edges and centres swapped but how to fix it? I tried everything I could think of until after 2 or 3 days and about 6 hours of attempts, I found a method. It certainly is not a pretty technique and I am not entirely sure why it works but I think it rotates all the equatorial edges and centres by 180º. With a huge sigh of relief, I can now put this one down.

Should you buy the Son-mum cube? Not if you are a beginner! If you have been playing with twisty puzzles for a while and have some experience of the Mixup cubes then definitely buy one of these. They move well and are fun to work out the basics. That killer parity may require some help and I have seen that there is a thread on the Twisty Puzzles forum about it already.

Tomorrow it will be back to work for a rest!

Sunday 13 May 2018

When is a Box Not a Box?

When it's an Assembly Puzzle!

It's NOT really a box!
The MPP guys are all out in Spain with Nigel at a 3 day extravaganza known as the Spanish puzzle party #1 and I am all alone back in the UK (Whack! Ouch! Sorry dear, I didn't mean to ignore you!) I am writing a blog post so that you all have something to read this weekend whilst Allard is gallivanting. Why am I not there? Unfortunately, I could not get those days off work and the cost was prohibitive for me when I consider that I have just been to Ikea for a puzzle display purchase which was never going to be cheap. Plus, Mrs S had just been absent in Edinburgh visiting her family and I couldn't immediately abandon her on her return - the fear of a Whack! Ouch! is just too great! From the pictures appearing on Facebook, the guys all appear to be having a great time.

Today, yet again, I am blaming Allard! A few weeks ago he wrote a review of a lovely little cube-shaped wooden thing from Japan. He had spotted in on Torito's site and combined an order with Big Steve. It is called the Kopa (or KO) box but don't be is NOT really a box! This is an assembly puzzle which just happens to be cube-shaped and has a cavity. A puzzlebox is defined by being an article intended for storage of items which needs an unusual sequence of moves to open it. This puzzle is has a central drawer that can be removed but there is no bottom in the drawer so anything stored will just drop out when it is pulled. Plus, a very big PLUS, this arrives in the disassembled state (as in the photo above) and the aim is to form a cube. It almost has maze-like properties.

The puzzle easily comes apart to reveal these pieces
The two outer pieces just pull apart and the central drawer can slide out. one outer piece and the intermediate are eternally linked by a dowel which sits in a square track around the edge as you can see above. When Allard was so enthusiastic about it, I contacted my usual puzzle pusher and asked whether he had any spare copies lying about. Of course he had one and Allard brought it back for me on his way back from Wil's King's day gathering. It duly arrived here and I couldn't resist settling down with it that very evening whilst "she who frightens grown men" and I watched some TV. Whack! Ouch!

The first thing I realised was that this thing is beautiful and then I realised that it wasn't going to be a pushover - it does slide together quite easily if you take the drawer out:

Easy peasy! Only if you don't include the drawer.
As soon as the drawer goes in the puzzle becomes much more difficult and just as Allard said, after about 10 minutes I was convinced that it was impossible. Sneaky bugger has got me to buy another impossible object! You can reach a stage where it is almost there but there is a cm or so still showing and no obvious way to get past this. I reread his review and realised I was at that early denial stage and that I should keep going. Now with this puzzle, nothing is hidden, there is no secret hidden mechanism. The entire thing is based upon 2 dowels moving around the edges of fact, there are 2 pairs of these dowels which seem to interact. This puzzle won't be solved by randomly moving the pieces because there are not many moves possible.

There are actually 2 really nice Aha! moments here. The first is when you notice a feature and have a sudden realisation that it could possibly go together if you can organise the captive pieces with the free piece in a certain way. How on earth can you make that arrangement? Think laterally? Think sideways? Backwards? What about inside out? Well, there is a particular thing that you need to do and suddenly a whole new set of possibilities opens up. Even then, I couldn't close the cube (NOT a box). The next Aha! moment is just as delicious...a sequence of maze moves lines it all up and suddenly with a lovely craftsman made slide it forms a cube with the drawer inside:

I have to say thank you to Allard for introducing me to this lovely and very clever NOT box/cube. It is a genius idea and beautifully implemented as one would expect from a Japanese craftsman. All in all, it took me about 45 minutes and Mrs S was actually impressed when I showed her the genius idea. She even told me that I was obviously brighter than I looked which is quite a compliment from her except, now that I think about it, this does imply that she thinks I look rather dim! I think I hide my lack of brains quite well! At the moment, both Wil and Torito is out of stock of these but I think Endo-san is being encouraged to make some more. If they do come up for sale then they are well worth your hard-earned cash.

When is a Cube not a Cube?

When it's a Shapeshifting Cubic Cuboid!

The Duo Axis Cube
A recent purchase from Calvin's HKNowstore included a bunch of cubes made by MF8. For some reason, my usual twisty supplier is unable to get MF8 puzzles but I can heartily recommend Martin's Puzzlestore for almost all other manufacturers. One of my recent purchases was one that I had seen back in 2014 on both HKNowstore as well as the Twisty puzzles forum and had been fascinated at the look of it but not really that interested in purchasing as it was nearly $200 as a handmade mod. I had completely forgotten about it when I recently saw that it had been mass-produced by MF8 and I added it to my "must buy" list. In that intervening 4 years I had completely forgotten even what was the nature of the puzzle.

After opening my nice package and admiring the contents, taking my photos and frightening myself to death with the Son-mum cube and especially the Unicorn cubes, I put the Duo Axis cube in my work bag to show off to my surgical colleagues who I am gradually convincing that I am extremely crazy but gifted. Whilst we were waiting to be given permission to start a case (we needed a post-op critical care bed), I took it out and investigated what it was. I could not recall the exact nature of it but knew that it was related to the Axis cube that I enjoyed in the past. One of my most read posts is my "Twisty puzzling advice to a beginner" discussion which focussed on where to go after one has mastered the basic odd and even order Rubik cubes. The shape modifications are a really fun challenging next step on your puzzling path and the Axis cube is a fun one to try and is now available as a 3x3 as well as 4x4 versions.

Too many layers
Looking at the puzzle above something did not look quite right - there were too many layers and some odd diagonal pointing pieces that didn't seem to line up with anything when turned. Over a few minutes of showing this off to my rather horrified spinal surgeon, we both came to different conclusions: I realised that this puzzle was NOT a was a cuboid modified into a cube and axis transformed at the same time! My colleague realised that I was completely nuts! Both of our realisations were correct! The puzzle we have here is actually a 3x3x5 cuboid which in my discussion of the classification of cuboids is a shapeshifter which will be made even tougher by the Axis transformation. Having realised the nature of it, there was nothing else but to scramble it:

Holy crap!!
Once I had scrambled it for a while I saw that those diagonal parts that would not line up with anything were not separating from each other (the 2 middle yellow parts - one with mf8 on it are 2 of them). It actually required me to use some simple 3x3 algorithms to make these line up and then I could get a full scramble. It looks really fearsome like that and luckily also quite attractive as it may be staying that way! Having seen the look of horror on my surgeons face, I then went off and anaesthetised my patient and only much later did I get time to play.

This "NOT a cube" is a really fun challenge for any twisty puzzler who has gone just beyond cubes and simple mods and is looking for something extra. As soon as you have mastered the basic cuboids (Floppy cuboid, Domino cuboid and Shapeshifter) then you are ready for this. The puzzle turns beautifully and is only spoiled by a tendency of the centre caps to fall out (which is easily fixed). Those split axial pieces add a nice extra challenge to it and the solve proceeds logically. It is very important to keep the base puzzle firmly in your mind because after any turns of an algorithm it is impossible to look at the puzzle and see what is next. This needs a good mind's eye. I definitely think that this is a great next challenge for anyone who wants something extra.

Congratulations to AJ and MF8 for some great challenges - this, and the other 3 above look fantastic. I do hope that some of AJ's other mods are mass produced because he makes some stunning puzzles which are just out of reach when handmade.

Sunday 6 May 2018

Perseverance Pays Off....

With a little help from a friend

Mrs S has gotten a little "miffed" the last week or so! In fact so "miffed" that the whiplash tongue was fully unleashed upon my person and quite a lot of Whack! Ouch!'s rained down on me! The reason for her ever-increasing ire? I might have "ahem" had a "little" splurge in the purchasing department. The cascade of new deliveries that arrived within a short period of time led her to ask me whether we had a) any money left at all? and 2) where I was going to put all of these new deliveries? It is true that my study currently looks like a bomb has gone off in it with puzzles and paperwork and journals absolutely everywhere with no obvious place for them to go. My big plan is a nice big set of display cabinets in a spare room - I have clocked what I need from Ikea and am ready to purchase them to solve ALL my problems!

Mrs S then questioned my puzzle manhood by asking whether I had solved all of the ones I had and then taunting me that I should go back to my unsolved ones and not buy any new ones! I sheepishly admitted that there were quite a few that I had not solved in several years despite many many attempts. I do keep returning to most of them and occasionally do manage to solve one. Here is a tale of one such event which occurred just this weekend.

Nearly a year ago (June 2017) the "Published professor of wood", Brian Menold, made a fabulous design from Christophe Lohe called Trenta. My copy was made with an Ash frame and gorgeous Mahogany pieces. When it arrived, there were 2 pieces held captive and the aim was to insert the third piece inside. "How hard can this be?" I thought to myself. and proceded to play with it and despite many weeks of play, failed completely! The 2 pieces in the frame are pretty loose and at least one rotation may have occurred during my fiddling. This was definitely NOT part of the solution and I might have rendered it unsolvable in the process. Every few weeks I would pick it up and play again with no result. A few people, including the great designer, noticed this puzzle sitting in my "currently playing with" pile in the living room next to my chair. Contributing to the mess, Mrs S would say with a laser burning stare!

Over the year, I have communicated with Chris and he has offered lots of encouragement and even suggested I send it to him to assemble so that I can proceed with it as a disassembly puzzle. Each time I have held off as I wanted to keep working on it. I was really amazed when he informed me that a friend of ours had even worked out a way using rotations to actually remove the captive pieces from the frame completely - however, I didn't dare try that at that time. Recently we have collaborated to purchase a bunch of puzzles from Aaron Wang (yes, I cannot resist good wire). He also sent me a few new ones from Bernhard and amongst them was a few gifts - a new prototype and a 3D printed version of Trenta in the assembled state for me to play with.

New wire from Aaron
New toys (incl Trenta)
From Bernhard
At last, I might have a chance to finally solve Trenta and in the process start to get Mrs S off my back! Whack! Ouch! Sorry dear. I did have a quick comparison of my copy with the one from Chris and realised that I had completely "buggered up" the start position and it was no wonder I had completely failed!

It was quite obvious that something was very wrong with my copy!
I proceded with a complete disassembly of mine:

Beautifully made! Maybe never to be assembled?
When I did this, it did occur as I made a number of fairly complex rotations that I might NEVER get it back together again but I was quite pleased with myself that I had managed it. Time then to go to work on the 3D printed copy. This started on yesterday evening in front of the TV and luckily for me, it is plastic and silent and the gently fuming Mrs S was not disturbed. I proceeded back and forth through the sequence in my usual way and got very stuck. There are a few paths but at each point, I came to a halt with no further moves possible. I was obviously missing something. If I was struggling with the disassembly then it was no wonder that I had failed at the assembly! After nearly 2 hours I found a, to me, VERY well hidden move and suddenly a new pathway was opened which progressively led to a solution:

Phew! That was quite a struggle!
I had gone back and forth a lot of times and was reasonably happy that I could repeat it. At that point, it was bedtime and I had to reassemble it and put it down. This morning, I began the day with a good gym session - Mrs S has told me that it may have been "for better or worse", "in sickness and in health" but it was NOT for "fatter or thinner"! If I get fat then she will certainly chuck me out and hence the frequent trips to the gym to ogle the babes, Whack! Ouch! Sorry! To achieve "the body less horrific". After my trip to the gym and a light healthy "not get me fat" breakfast, I went back to the Trenta so I could finish it off for today's blog post. Except I couldn't remember the sequence and had to work it out all over again. Damn! I am not terribly bright! That took me an extra hour of sweating and swearing under my breath. But at least I knew the orientation of the pieces inside the frame now and just had to work out the key rotational move(s).

You very nearly didn't have a blog post to read today! Working on the plastic copy, I tried to work out the moves to remove the captive pieces and for the life of me, I couldn't do it. There is one obvious easy rotation but as usual, this gets me nowhere. The correct move is unbelievably hard to find. I then moved to the wooden version and tried to insert the pieces to get the start position as shown above and....I couldn't do it! There was lots of swearing and for a while, I thought that I might just have to send the puzzle back to Chris for him to assemble. Mrs S began to laugh at me for all the muttering and my frantic twisting and turning. Ridicule from the wife was obviously what I needed because all of a sudden I found the required rotation. That move is incredibly hard to find and requires the pieces to be placed with tremendous accuracy and turned exactly so. There is no scraping and it is not tight but it will not work if not just right.

With the pieces correctly in the frame, it was just a matter of backtracking the original solution. Even that is not easy and I finally, after nearly a year of effort, had the puzzle solved.

2 fully assembled Trenta's
At last! The question now is do I dare disassemble it again? I think I must - the little voices are saying that I need to prove that it was not a fluke!

Thank you, Chris and Brian, for a fantastic puzzle. Thank you, Mrs S, for letting me live a little longer to tidy up the puzzle collection! Whack! Ouch! I wasn't being sarcastic, I promise! I will work on the backlog that has recently increased a lot! Whack! Ouch!