Motivation From The Cutlery Drawer

Oskar's Nested Burr

Two pieces removed and I shy away

I received this 3D printed puzzle back in December last year. I didn't order it because I actually had never heard of it. I know that it was made by Mike Rollberg but I am not sure how it came to be in my possession. It must have been a gift from someone and I'm very sorry that I cannot remember who sent it to me. It must have  included it in another delivery. To whoever you are, thank you very much - I hadn't realised up until this week how good a puzzle it actually was. Thank you Mike for printing this and getting it to me. Of course, being a puzzle design by Oskar van Deventer, I should have realised it was going to be fabulous! It's an 18 piece burr but completely different to the usual design and much more interesting than most 18 piece burrs.

I left this in our correspondence tray that sits in our kitchen for a few days after it arrived and picked it up intermittently and took a couple of pieces out, realised what was going to happen if I progressed further and stopped there quickly. I put it back in the tray and weirdly it attracted the cats. There is something about the texture of 3D printed puzzles that they seem to love - I heard a funny noise behind me one evening and saw a cat at the puzzle, shooed her off and picked it up to check for bite marks. No damage but it was covered in cat saliva! YUCK! I dried it off and moved it to the cutlery drawer where it sat on top of the small knives for quite a long time. 

I picked it up periodically because I kept being reminded it was there every time I set the table for a meal. At some point I think I even removed the first 6 pieces and hurriedly put them back. It gets even more frightening as you take out more pieces because stuff does get a bit loose. Having said this, as long as you hold it properly it doesn't fall apart.

Eventually Mrs S started to get a bit annoyed having a puzzle permanently in the cutlery drawer. She understands the cat slobber situation but doesn't want puzzles in the house kitchen any longer than they have to be there. A week or so ago, I got shouted at (again) and the puzzle was forcibly removed from the cutlery drawer and I was told that if it was seen again then I might need a surgical removal of puzzle from an orifice that is not intended for that direction of travel. 

Motivation had finally arrived and yesterday I progressed through a sequence of piece removal to get myself a nice pile o'pieces:

Now that looks intimidating

Still intimidating!

What about the reassembly? Interestingly, the disassembly has a coloured rhythm to it and as long as you remember that rhythm then you have a big help with the reassembly of the burr. A bit of experimentation is required to work out the orientation of the pieces but it's usually fairly easy to work out when one is pointing the wrong way or needs rotating 90º along its axis.

After about a half hour of play, I had put it back together - it's really very clever and delightfully tactile to play with. If you get a chance to play with one of these then jump at it (you can download the files to print it yourself from Oskar's file repository). It's really rather clever!

An Epic Eyckmans Extravaganza

Dikkop	Cannonball
Hollow 15	Poolster

It doesn't seem that long since the last Pelikan release - I just don't know how they maintain such a punishing schedule and keep the quality so very high! Despite producing another huge batch of puzzles in just over a month, they are all absolutely stunningly made with a fit and finish that can only be described as perfection. There are 7 new puzzles to be released in this batch and the first four of them to be reviewed are a progressively more complex and very interesting set of 6 piece burrs.

Alfons Eyckmans designs some of the most amazing interlocking puzzles and burrs there are. I have a huge collection of his designs produced by Pelikan, Alfons himself, and also the late Eric Fuller. He designs puzzles that can be very very complex and difficult to solve but also creates easier designs that have something very interesting and fun. Most puzzlers enjoy a nice burr but don't enjoy extremely high level versions. Jakub, Simona and the team always choose puzzles that have something special and fun about them and are not just very difficult high level burrs. The Eyckmans puzzles in this release are perfect examples of this. They are all clever variants of the 6 piece burr which makes them especially interesting to many puzzlers.

Dikkop

I Started with Dikkop (translated from Dutch to mean Fathead (for obvious reasons). I initially thought that this one was a rather complex 3 piece burr. It is beautifully made from Wenge, Padauk and Acacia and I was very glad that I picked this one to start with. It's nice and chunky and easy to manipulate the pieces. As soon as I found the first move I realised that what looked like one giant burr piece in each direction was two sticks lying side by side. The "fat heads" prevent the pieces sliding out too easily and do restrict some of the moves. The disassembly takes 15 moves (9.2.2) and is actually a very pleasant exploration. It is a pleasure to work out which move comes next with very few blind ends. It remains stable right to the very last piece being removed which is very gratifying as it means that a beginner puzzler can keep an eye on where pieces are and understand how they lock together all the way through the disassembly.

It's really quite clever

I then scrambled the pieces and from a combination of my very poor memory and logic, I was able to put it completely back together from scratch. As a result, this is a really nice puzzle for beginners to burrs as well as experts. It will also look very impressive on display.

Cannonball

Made from a very dark and beautifully grained Acacia, this lovely clever 6 piece burr has a captive centre "cannonball" made from a vibrant Purpleheart. This is another puzzle where the sequence is fun to discover and not too difficult to achieve. I found the first move reasonably quickly but struggled for some reason to find the second move. I think it was because of the way that I was holding the puzzle. Once I had found that move the sequence sort of unfolded in front of me and I was able to remove the first piece after 7 moves. The rest came apart quite easily and again was very stable whilst each piece was removed. The cannonball proved to be unexpected shape which did explain why it was held in position so well.

Now, that's an odd cannonball

I am rubbish at burr assembly but was able to put this back together from memory whilst the pieces were arranged in the order that I took them out of the puzzle. Once I had arranged them for the above photo, I had lost track of what went where and how they went together. I was now unable to put it back together (at least there was no time for me to do it before having to write about them) so a BT file was used. I do actually think that anyone who is reasonable at burrs should be able to assemble this from pieces with a bit of thought. I plan to try and do it myself when I have finished working on the rest of the batch.

Hollow 15

Hollow 15 is a really interesting 6 piece board burr which is a huge step in difficulty from the Dikkop and Cannonball. This is probably less good for beginners but is great fun for the more experienced burrista. Entirely made from a really lovely Acacia, the whole point of this is that the centre of the puzzle is empty and after just a few moves, you can see inside at how everything is interlocked. The interesting thing here is that two of the boards are formed as complete rings with no gaps and the others have small gaps in one edge. The trick will be to move the pieces far enough apart from each other to  make space for the gaps to be aligned and unlock them form each other. I found the early moves with very little difficulty but after a few moves, a whole lot more are opened up as possibilities and the puzzle pieces get extended further and further away from each other. This makes it rather hard to keep control of them as some of the seem to want to rotate or sag depending on how you are holding it. I suspect there might be a rotational shortcut somewhere in this puzzle but I was very careful to avoid rotations.

After a few moves, I realised how complex this was going to be and I started using my usual to and fro technique to try and keep track of what I had done. Once I was about 6 or 7 moves in, a whole lot of movement suddenly became possible and after wandering up one pathway, I found I couldn't find my way back to the beginning - GULP! No option other than to continue my exploration. Luckily at this point the puzzler can see everything that is going on inside and can try to plan a move or two ahead. I did get stuck for a while when I couldn't find a needed move and realised that it was because the fit of the pieces was so exact that I needed to align them absolutely perfectly to achieve the required move. After I realised this progression was steady and fun until the first pair came out. It did sort of collapse at this point but still well entangled. The separation of the last four pieces was still fun but needed a bit of control.

The pieces look simple but they are not

This is a very impressive puzzle to disassemble and once you see all the pieces, it is very impressive that the Pelikan team have managed to create it with such perfect accuracy. With a construction like this even a tiny error in the angles will result in an impossible to move puzzle but this is simply perfect. The name Hollow 15 comes from the fact that it requires 15 moves to take out the first piece (level 15.2.4.3.3).

I definitely needed Burrtools to reassemble this one and I suspect that the vast majority of you will as well. Luckily making the BT file is great fun.

Poolster

Poolster is the final puzzle by Alfons in the release by Pelikan. Made using Merbau (aka Borneo Teak) and Movingui (aka Nigerian Satinwood), it really confused me when it first arrived. I could not tell what it was as on arrival the pieces with square holes had all slid outwards by one voxel making the puzzle look rather frightening. I then realised what had happened and squeezed them all together to achieve the correct shape that you can see above. I initially thought that the centra sticks were a captive 3 piece burr but quickly realised that each central cube protruding from one face is connected by a complex arrangement to the square on the opposite face.

There is a lot of movement possible from the beginning with this puzzle and it will require a systemic approach to ensure that you try each set of possibilities as far as they can go before backtracking to the beginning and trying another one. I found the reinforcing dowels quite useful in keeping track of which pieces I had moved and in which direction. The puzzle remains remarkably stable through the initial exploration and removal of the first couple of pieces (level 10.10.7.2). After that it becomes easier as you can see everything that is happening inside. Once in pieces the impressive nature of the design and the craftsmanship becomes very apparent.

Perfect alignment to make this one work

I think that very few puzzlers will be able to assemble this from scratch but I would be interested to hear if any of you manage this. I needed to resort to Burrtools again but it's a fun one to put together. Like Hollow 15, this is probably best for more experienced puzzles but if you like to collect variants of the 6 piece burr then this is a good one for you.

Burrs With A Twist

Literally... With Twisting Movements In Them!

Trust Steve to produce something funny with an extra twist in it!
Boarin' Burr - the boars appear on every surface

First of all, I MUST give proper attribution to the origin of last weeks main puzzle. The wonderful version of the Diagonal Star puzzle that I wrote about last week should actually be named the Sequential Cube. It was designed by the amazingly talented George Bell as a variant of Lee Krasnow's very rare Sequential Star. Practice does improve things with this puzzle - I can now solve the Sequential Star version and the 9 move version quite easily. The 14 move seems to be more problematic for me but I keep trying. If you get a chance to play then go for it - it's very mind-bending.

I should also point out that we have a new blog in the puzzlesphere - Fraser, whose name I forgot last week, has started an unassuming little place on the internet where he asks the useful question: Can an idiot solve it? This looks really useful to me - I have been an idiot my whole life (I'm pretty old now) and am rubbish at puzzles. I will be using his advice to see whether I should bother trying to solve some of the puzzles I see on the internet. Go show him some love/views! 

Today, I am writing about a couple of puzzles that look like burrs and sort of work like burrs in that they are composed of interlocking sticks but there is something twisted inside both figuratively and literally.

The IPP provides all of us with a list of puzzles we want. I am lucky enough to be given a few of them every now and then. Everything that the TwoBrassMonkeys do should be added to your list of things you want because there is always something special about them. Here, I have Steve Nichol's exchange puzzle. He designed a burr with some extra challenge to it. The theme is both the boars that are often found zooming around Italian towns causing havoc (Steve, cause havoc??? Oh yes! everywhere he goes) and of course, the name refers to the fact that pieces rotate like bores. and effectively double lock the burr sticks. Steve likes interlocking puzzles but always seems to want to make something a bit more interesting than a standard version. He has created them from hexagonal sticks and round sticks to confuse you. He's made odd movements and multi-step sequential discovery burrs which won my puzzle of the year for 2024. There seems to be no end to the ways that Steve wants to play with your head. In this case he has a burr with boars that got bored and bored their way inside your burr:

If you push on a boar then it unscrews from the puzzle!

This is interesting and very ingenious. It is quite reminiscent of Oskar's screw burr but extra confusing! Obviously this cannot be entered into Burrtools so you will need to be careful. Luckily everything is sequential and you quickly can produce a bunch of very odd looking sticks. Make sure that you mix them all up so that you have no idea what came from where and what orientation they were in when you started. This was one of my mistakes initially. It did not occur to me that stick orientation would be that critical when I scrambled them and I really struggle to reassemble it the first time.

There's nothing boring about this puzzle!
I have absolutely no idea how he designed this

The multi-coloured sticks can be assembled into a six piece burr in lots of ways but the locking mechanism comes from the bores/boars. Take a look at the notches in the sticks and with a little care it is possible to put it back together again with only a little trial and error as sticks may need switching end over end.

Great fun, with a twist - just as we would expect from Steve. Thanks mate. I assume that this will be put up for sale at some point. Keep an eye out on the Two Brass Monkeys website.

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SV Burr by Richard Williams (P91 puzzles)

This burr is a fascinating design by Richard Williams. The aim is to disassemble and reassemble the burr and, most importantly, in the process, understand why it has the name SV Burr - what is SV? I bought it at an MPP last September having watched lots of people struggle both with the disassembly but also get caught out by the reassembly. I made sure not to watch what they were doing and what they had found along the way. I took it home and began playing. Initially it has absolutely no moving parts and takes quite a bit of pushing and prodding to make your first move. Very quickly a tool is o=in your hands - not what you would usually think of as a tool - it's just a bolt. What can you do with a bolt in a burr?

There are a couple of holes in the puzzle where you can poke the bolt but no real clue as to whether this is having any effect. After poking and pushing and screwing and unscrewing I did find something and then movement happened. Yay! After that, nothing else was possible but I did have another hole. I "screwed" my courage to the sticking place and put the bolt in the hole and closed up the burr in the hope that I could now use gravity to pull or push something inside. Well, that was a stupid thing to do because now I couldn't move anything. After a day, I contacted Rich to see whether I was on the right track and apparently I had been very stupid! He had never even considered that anyone would be so stupid as to do that and advised me to try and undo what I had done. As always, never underestimate my stupidity! Eventually, I did manage to undo the mess that I had got myself into but it took a couple of days - phew! Then, of course, there was more stupidity! I tightened something to much and stripped some of the plastic off - this rendered my puzzle non-functional! Aargh! Yep, I'm an eejit!

At the next MPP, I had to give it back to Rich to fix. I eventually got it back at the last MPP and promised to be more careful with it this time. I started again determined not to prove myself too foolish. I did the first moves again and achieved my sliding burr moves. This time I did not lose a piece inside. I worked on various other possibilities and somehow managed to get more movement. I was screwing and unscrewing but not understanding why it changed things inside. Despite that, I managed to progress. At some point a new too dropped out and I had no idea where it came from. A little exploration revealed a hidden compartment which had been the hidey-hole. The new item was an odd looking tool but there was only one place it could go and in it went. In fact it went in and out several times causing some more screwing movements and another piece came off/out. Turning the puzzle over caused yet another tool to drop out and this time I had noted where from. After searching about there was only one place to try it and yes, more screwing about. Then the final piece was removable and the burr came fully apart:

A six piece burr?
Nope! A lot more than that.

After this it becomes clear what the SV stands for - I'm not going to give it away. You need to get your own copy of this and work it out for yourself. Thanks Rich!

So we have to burrs that have lots of twists in the tale and twists in the puzzling. Fabulous - I need to lie down now as I'm really quite dizzy.

Pelikan Summer Release Part II

Continuing what I started last week. Jakub sent me the latest offerings which I suspect will be released later this week. I showed them off at the MPP yesterday and a several people were completely bamboozled by them. 

Minima For Frederic

Minima for Frederic by Dr Volker Latussek

Oh, Yesssss! More Minima puzzles! By now, you will all have realised that I absolutely adore the Minima series and all its' variants. Initially they were designed by Frederic Boucher to have a box with a 2x2x3 cavity and varying numbers of oddly shaped, but small, pieces to be fitted inside the box. Usually the aim was to make sure all the holes were occluded and at times the solution required interesting rotations of the pieces. Some of the puzzles had clever slots in the box to facilitate the rotations which did sometimes make the puzzle very confusing. One or two of them had extra "bits" attached to the pieces. Other designers jumped on the bandwagon with all sorts of interesting shapes and challenges. I have loved every single one of them so far. There is something very special about Volker's brain - he sees shapes and movements that almost no-one else can see and produces challenges that are incredibly difficult and interesting to explore. He created the amazing Minima-Flop and I have been waiting with bated breath for another special Minima from him. Here we have, not only another fun Minima designed by Volker, but also a Minima which he felt was good enough to be named as a tribute to the originator of this series, Frederic. Jakub and team have manufactured it from a very beautifully grained Oak and Wenge. Volker wrote this about the puzzle:

"A few years ago, Frederic Boucher wrote to me and invited me to contribute to his MINIMA series. To make my decision easier, he suggested that I didn’t have to fill the box’s internal volume strictly as 3x2x2, but could also consider using half-cubes and thus interpret the box as 6x4x4. I still remember well how I expressed my confusion to him about this; from my point of view, this offer – though certainly well-intentioned – contradicted the originally intended minimalist design concept of a 3x2x2 box, given the generous interpretation of the strict guidelines.

Now we all know what outstanding ideas Frederic was able to realise in his MINIMA series. Nevertheless, I wanted to resist this temptation and only agreed to the project under the strict conditions. I’m still pleased with the result today: MINIMA-FLOP, especially as I was able to completely fill the 3x2x2 box with four identical Tricubes and incorporate the FLOP moves – which were so important to me – into the solution. In fact, I was very satisfied with the result, and I think Frederic was too.

However, when I was recently playing with one of my 14-piece complete sets of building blocks of the same size, I checked whether six of these building blocks – each consisting of one cube and two half-cubes – could be used to fill a 6x4x4 box in an appealing way. I was pleased to find that, out of the 924 possible arrangements, only 13 filled a 6x4x4 volume in 50 different ways. For whatever reason, I then looked for suitable 3x2 openings – which I’m familiar with from my FLOPs – in order to offer a challenging and unique solution. I was so impressed by the result that, despite my initial reluctance, I asked Frederic if he would sponsor it. To my great delight, he agreed immediately, and so Pelikan is now able to release this puzzle under the name MINIMA FOR FREDERIC. I’m very pleased about this, and I think Frederic is too."

As you can see above, the puzzle arrives in a special transport configuration which took me quite a long time to actually unravel from the box. It is so nice to have this extra challenge. It reveals the rather unusual pieces to be packed inside:

Six interesting pieces to be packed.

Having managed to unpack the pieces, I realised that the assembly was going to be a huge challenge. Especially when you remember the rest of Volker's incredible rotational packing puzzles. I actually struggled to make the 4x4x6 cuboid for a while and when I did construct one, I placed it alongside the box and looked for ways the shape could possibly be taken apart through the holes. The cuboid could be arranged in 8 ways to try and interestingly, only 3 of them had even a single removable piece which was very helpful but to my horror, none of those positions would allow a second piece removal (even with interesting rotations). The constraints of the box just wouldn't let another piece out. At this point I was worried that there might be dozens of assemblies of the pieces to then try and find a way to get them inside the box. Because of my time-constraints, I went to Burrtools to look for cuboid assemblies. There are just 2 and I had found the wrong one first. 

I used BT and constructed the correct assembly and looked again to see how it could be disassembled using the various holes in the walls. 

The first piece obviously has to just lift out the top hole but after that there is a sequence of clever rotations using the holes until there are just 2 pieces remaining. Those two pieces did look impossible to place inside but obviously that was going to be the main challenge that Volker had intended. Time to set to proper work...

At this point, I had my assembly order positions and then "just" had to work out how to get the first two pieces into position. I tried for days to get them inside and in position for the third piece to be placed but I just couldn't get them into place. I went back to the cuboid several times to see whether I had missed an alternative assembly or orientation but it was correct. There is plenty of room in the box but those two pieces need a very clever and very specific set of moves around each other to get them into place. After 3 days of trying, I finally packed them into place and after that the rest rotated into the correct placements fairly easily.

My Goodness! It's absolutely brilliant!

If you like Minima puzzles then you must buy this. If you like Latussek puzzles then you must by this. Hell, if you Like puzzles then you must buy this! It is up there with the best Minima puzzle designs by Frederic - it is a very suitable tribute. Thank you Volker.

Fatomino

Fatomino by Dr Volker Latussek

This gorgeous creation has been made by Pelikan using American Walnut and a rather fabulous Zebrano. As soon as I saw it I was immediately taken back to one a fabulous packing puzzle by Hajime Katsumoto in 2016, Penta in a box. 

In the original puzzle, the cavity of the box was a 3x3x3 cube and there were 5 planar pentominoes to be fitted inside allowing the lid to close over them. It looks pretty easy but there is a catch - the lid cannot close over any piece in the top row at the front and any piece in the lid cannot close over an adjacent piece that would end up behind it. This simple looking packing puzzle required quite a lot of thought. So what could Volker possibly do to improve on such a simple but fun design? Volker wrote his thoughts about it:

"It’s already been 10 years since Hajime Katsumoto caused a stir with his PENTA IN A BOX – a brilliant idea to pack five of the twelve flat Pentacubes into a 3x3x3 box with a clamshell lid. As I don’t collect puzzles myself, it wasn’t until years later, during a joint visit, that I was able to play with Götz Schwandtner’s copy at Bernhard Schweitzer’s house. The interplay between the Pentacubes and the clamshell lid feels really good. And the chosen mix of the five Pentacubes is truly something special. 

I’ve been experimenting for some time now with the FATs – the 15 Pentacubes, each of which is described by a 3x2x2 envelope. In doing so, I naturally also recalled PENTA IN A BOX; interestingly, I hastily dismissed it again because I concluded that there couldn’t be five FATs that could fit into a 3x3x3 box with a clamshell lid. Something very fundamental went wrong with this thought experiment. How foolish of me, considering that there are 262,344 cuboid arrangements. An obvious mistake. 

For with FATOMINO and its one of potentially 303 combinations of five FATs, it is even possible to achieve a filling with a unique solution. What’s more, I maintain that there is no other combination with a unique solution. In this sense, FATOMINO, modelled on PENTA IN A BOX, is unique. In fact, I would very much like it to stay that way."

I did ask Volker why he called the pieces "FATs" and apparently it originated from George Miller who described the pieces as being able to fit in a FAT cigar box. It is just a way to refer to the NON-planar pentominoes. The pieces are very interesting and very satisfying to play with:

A beautiful hinged box and 5 non-planar pentominoes

Recalling the problems that I had with the original puzzle, I knew what sort of arrangements I had to attempt to create:

Not going to work

The aim was to make 2 separate packings that can be folded onto each other with a hinged edge. This sounds very simple but it took me quite a while to realise that the intersection of the leading edges as the hinge closed was really causing a problem. I had to hunt for a very particular arrangement. It would be tempting to brute force this with Burrtools but it shouldn't be necessary. After a few failures, you should be able to think of the type of organisation that you need and then hunting for it is tough but fun.

Yet again, Volker produces a variation on an award winning puzzle and manages to make it even better than everything that has gone before. This is a MUST have puzzle as well! It is simply superb. If you enjoyed Penta in a box then you will adore this one.

Flummox

Flummox by Benjamin Heidt

This is the second burr in this summer release by Pelikan. Both of them have been sent out in an unsolved position and the aim is to created the solved shape before then completely disassembling and then reassembling it fully. Flummox is well named as it is VERY difficult and will really challenge even the best burrista's. It is a caged 6 piece burr with "extra constraining pieces" and a stick length of 8 voxels made from a very striking combination of Zebrano, Purpleheart and Maple. When it arrives, one of the burr sticks is protruding up out of the box and will not simply push back into place.

It took me a good ½ hour of fiddling about (there are quite a lot of possible moves of the other 5 pieces) before you can make enough space to sink the protruding stick back to flush with the cage.

After this, obviously, the challenge is to disassemble the burr completely into 6 sticks and a frame. This is not for a beginner to burrs. It really is a very complex disassembly and there are a LOT of well disguised moves including lateral as well as forward and backward moves. The disassembly level is 30.1.2.3.2.2. Whilst that doesn't look too bad and I would usually say that is an optimal number of moves for a satisfying burr but in this case, with a frame, and being very difficult to see inside, this is VERY difficult. It's very rewarding when the pieces start to come out but even after the removal of one or two of them, the remainder remain very difficult to remove. This will be impossible for most puzzlers to reassemble without resorting to Burrtools but creating that file will be an extra challenge for you.

That was a massive challenge!

Fudou

Fudou by Frederic Boucher

Yes, another incredibly tough challenge by Frederic Boucher. I had to ask Jakub what the aim was. The Bubinga pieces arrived all nicely packed in the tray and I wondered whether we had to create some sort of structure that would stand up. I should have realised that this had a much simpler premise - the aim is to pack all the pieces into the tray in such a way that none of them are able to slide around. The triangular notches cut into most of them will allow them to interlock at 45º angles to each other and will ensure that they can be placed against the wall of the tray to prevent sliding. i.e. pack them into the tray but not orthogonally - simple? Hell, no!

I am terrible at anti-slide puzzles. I have managed to find a few very interesting ways the pieces can interact. The aim seems to be to find which pieces will fit together so that their corners reach the sides of the tray and then won't move if others are matched up to do the same. There must be a logical way of thinking about these but I have no skills in this sort of puzzle. It is a fun thing to play with but for me, I have made almost no progress in the 2 weeks that I have been playing.

For you clever puzzle enthusiasts this should be a massive challenge. Anything from Frederic is going to be very rewarding.

Pelikan Waits For No Man!

Having returned from the IPP, sneaked my new puzzles in (in their rucksack) and secreted them around my study, I started to work my way through them. I thought I was doing pretty well and felt I might just manage to get a few blog posts in before anything else arrived (I might have a couple on the way). Just when I thought I was safe, Jakub contacted me to say that he was ready with the next batch of Pelikan wonder. My first thought was: "Hooray! More gorgeous beauty and fabulous, difficult challenges" This thought was rapidly followed by another: "She's going to kill me!" Luckily, this time, the box arrived, and it was smaller than the previous ones. She who must be feared thought there were fewer puzzles in there, but don't tell her...they have just been packed tighter. Gulp.

Matruschka

Matruschka by Benjamin Heidt

3 tiny pieces make a stand

There have been quite a few creations on this blog from Benjamin. He designs interlocking puzzles and burrs that are just the right difficulty level for most puzzlers, with some very interesting design features and a lovely sequence to explore. Many burrs are much too complex for most due to multiple long blind dead ends, or alternatively have too simple a sequence and no challenge. Benjamin always gets it right, and Matruschka is a beautiful example. This chunky puzzle is made from Wenge, Cherry and Acacia with a diminutive stand made from Merbau. Looking at it, I was slightly confused as there only appears to be Wenge and Cherry visible, but after a couple of moves, the reason for the name and the extra wood type becomes apparent. A matryoshka doll is the name for the Russian nested dolls, but here Benjamin and the Pelikan team have taken the idea and altered it a little bit to make a nested burr.

The initial exploration reveals quite a few possible moves, and I was worried about having lots of long blind ends to explore, memorise and discount on my way to the correct solution. You can be reassured that, as usual, Benjamin has got it just right. There are quite a few possible ways to start, but the sequences are short before they stop, and you are forced to look elsewhere. The tolerances of the burr manufacture are superb, with everything sliding beautifully. The correct sequence is very well hidden, but once found, you are quickly on your way to the disassembly, and more and more pieces can be removed after you look for the unlocking sequence. The burr within a burr is revealed nicely:

Acacia burr nested within the final 3 large burr sticks

Once the inner burr is released, it can also be disassembled into 6 very beautiful sticks and then the whole lot displayed. 

 

That's a LOT of burr sticks!

The reassembly would actually have been possible for me without the use of burrtools, as I had sequentially removed pieces and placed them in their correct order and orientation on a table. I think most puzzlers should also manage the reassembly if they are careful to do this. Unfortunately, a cat decided to run across my carefully arranged table and scatter the sticks widely. A few unsafe for blogging words were uttered, and Burrtools was going to be my next step.

Once you have done the reassembly that you found then it is time to do it all over again! The 3-piece stand that is interestingly burr shaped can actually be reassembled inside the 6 piece burr so we end up with a burr in a burr in a burr! This is simply amazing!!!

This is a wonderful challenge for all burr aficionados, just the right difficulty level! With an extra twist at the end.

Surround Wil

Surround Wil by Frederic Boucher

There seems to be no end to the puzzle design skills of Frederic Boucher - there are several of his designs in this upcoming Pelikan release. This delightful packing puzzle is fun and should be perfect for all puzzlers of all levels. The puzzle is made from Acacia and a very vibrant Purpleheart. It is quite reminiscent of some of the packing puzzles by Yuu Asaka. There are 4 longer pieces with curved ends, and half-circles cut out, plus 5 disks, all to be fitted into a tray that is too small to take the long pieces side-by-side. If you look at my photo, the top-most large piece is tilted as it doesn't fit in.

This inability to fit the pieces side by side is a big clue that you need to get inventive with how the big pieces can be organised. I found a lovely way to get them all in the tray, but then the half-circle cutouts had been filled, with no space left for the disks. Time to think© and get creative. There is a lovely Aha! moment in this one, and it is very satisfying to pack them all in. This will be coming to work with me to challenge my colleagues - it's perfect for casual puzzling..

T Time!

T Time! by Frederic Boucher

This wonderfully clever packing puzzle by Frederic had me fooled for most of the week. It looks like a simple tray packing puzzle, but there is MUCH more to it. There is a 5x5 space inside the tray and 5 T-shaped pieces to be fitted inside alongside a 2x2 smiley disc. That doesn't look too difficult until you realise that the tray is covered by an acrylic cover with a T-shaped hole in it, in one corner. This explains the nicely curved corners on the pieces - they need to be inserted and manipulated using the holes in the bottom of the tray, plus some use of gravity, until they are in position. There will obviously need to be some rotational moves as they cannot possibly be arranged in the same orientation as the hole in the lid. It doesn't take long to find at least one (if not a few) possible arrangements of the pieces in that 5x5 space, but then the fiddly task of actually getting them into place begins, and, OMG, it's difficult! I spent several days trying everything I could to pack them all in. Nothing would work, and I had to stop for a bit and think© again. 

Finally, after several days of work, I had a special thought (unusual for me!) and realised that there was something very unusual about the design. My jaw dropped when I finally succeeded - Frederic is a genius!

Convolution Cube

Convolution Cube by Stewart Coffin

Convolution ball

Over the 15 years of this website, I have reviewed several versions of the Convolution puzzle by the amazing Stewart Coffin. This incredible interlocking design is not solvable by Burrtools due to the requirement for a rotational move with one of the pieces (does that make it a TIC?). I have a version from Brian Menold and a fabulous spherical version from Pelikan.

I personally would say that a Convolution (as well as its associated cousins, Involute and Involution) should be part of every serious puzzler's collection. All 3 are essential. If you don't have this, then you owe it to yourself to buy a copy. The Pelikan team have done a wonderful job creating this out of multiple different beautifully vibrant woods and the fit is just perfect!

Only 7 pieces but great fun!

The next bunch of puzzles will be reviewed next week - they include more from Dr Volker Latussek, another from Benjamin Heidt and then yet another unusual puzzle from Frederic Boucher. Wish me luck solving them!

Pelikan Begin 2026 With An Extravaganza

There are a LOT of fabulous puzzles here

On Monday, February 2nd, 2:00pm CET, Jakub and team will be releasing the first set of wonderful toys for 2026. This release has some truly incredible puzzles to keep you busy for a while. As always, they have been made from glorious woods with incredible precision. The choices of challenge are all superb,

Grid by Lucie Pauwels

Prison by Lucie Pauwels

Donjon by Lucie Pauwels

Yoga I by Benjamin Heidt

Conundrum by Benjamin Heidt

Minima-Flop by Dr. Volker Latussek

Minima XIII by Frederic Boucher

CUBI series by Frederic Boucher

I have had these puzzles for a couple of weeks and have been hard at work solving them so I can review them in time and help you make a choice. Whatever you choose, you cannot really go wrong here. 

Conundrum

Conundrum by Benjamin Heidt

Here we have another fascinating burr by Benjamin Heidt. The box from Pelikan says "mixed woods" but the pre-release gave more information - it has a beautiful set of dark woods (Bubinga, American Walnut, Purpleheart, Wenge and Padauk) arranged into a caged burr containing 4 sticks held vertically alongside each other in a frame. Initially it looks like the frame can split into several more pieces. As usual, Benjamin has created a fun logical sequence of moves that follow each other very nicely without leading you too far into long dark pathways. as you explore, these pieces dance around each other in a circle and go back and forth. After a decent sequence the dance stops dead and there seems to be no way forward and it looks like you need to go back and explore the side paths further. This won't get you anywhere so after a little while of returning all the way back to the beginning and trying alternative starts you realise that there must have been a hidden move at the end of that dance. There is a lovely Aha! moment when you find the cleverly hidden move and then suddenly the dance can continue to the removal of the first piece. The removal of the remaining pieces is now a nice logical sequence that you can work out by looking inside the space left after the initial removal. At level 21.3.3.2 this is a fabulous fun challenge with a lovely Aha! moment to keep any burr solver happy.

The reassembly would be impossible from scratch for all but the best burr solvers but having gone back and forth multiple times, I was able to put it back together straight away from memory with only a bit of experimentation. Fabulous!

Prison

Prison by Lucie Pauwels

There is something compulsive about the packing puzzle designs from Lucie Pauwels! This wonderful little challenge has been beautifully created by Pelikan with a wonderfully contrasting Bubinga frame (prison) and white Maple pieces. The prison consists of a simple 3x3x3 cube but is made much more complex by the addition of a single voxel hole in the floor and ceiling which also have to be filled - on top of that the openings to be fed through are partially obscured on all sides leaving a 2x3 gap on each face. The pieces are a variety of small simple shapes - there are 7 pieces in all to be placed in the prison. I thought initially that this should not be terribly difficult but the slightly limited entry and the need to fill ceiling and floor holes turns this into a proper challenge. Burrtools tells me that there are 151 possible assemblies and I struggled to find even one of them! I think it must have taken me a good 30-45 minutes to get my first one. Working outside the box as is traditional was not helpful as it is really hard to hold the pieces in place as you progressively add more of them. I was forced to work in the prison to use the prison bars to hold the pieces as I added extras. I frequently seemed to be making progress only to either have a final shape impossible to add into the puzzle due to blocking walls or the final gaps were split into several shapes. I had to use a bit of thought to work out an initial approach and then a lot of trial and error to get the first assembly. There is plenty of repeatability here to look for different assemblies.

Late update!!!!

Having posted this article, I was contacted by Lucie this morning to tell me that I had completely misunderstood the nature of the puzzle! Jakub and Simona don't give me the instructions. I had assumed that this was a packing puzzle but I can now tell you that the packing element is a secondary challenge (and not even the toughest challenge). It would appear that the top surface of the prison is held on with rather strong magnets and it can be lifted off to give very good access to the cavity of the prison. The true aim is to place all the inmates inside the prison and then replace the roof. This sounds easy and it really is BUT the pieces need to be placed in such a way that once the roof is back on, the pieces cannot slide out. Yes this is an anti-slide puzzle and looks like a very difficult one. I will need to go back to it soon.

Donjon

Donjon (delivery positions) by Lucie Pauwels

Donjon (or dungeon) is yet another very VERY difficult puzzle from the warped mind (we have one prison and one dungeon in this release!) of Lucie Pauwels.  Made from beautifully contrasting Ash and Wenge, the first challenge is to remove all the pieces from the transport positioning. This in itself was a major feat due to the very limited access! The aim is to place all the "prisoners" through the entry down below the surface into the dungeon and lock them in. The dungeon itself is just a 3x3x3 cube but the entry is ferociously blocked by a complex crowning door leaving only a 1x3 entry gap on each side. It is made even tougher by the fact that the entry gap is very narrow (smaller than a finger) - controlling the orientation of the pieces is going to require considerable dexterity. Having eventually taken all the pieces out, I was seriously worried about my ability to get enough back in even for storage, let alone solving it. I started assembling my 3x3x3 cube and quickly realised that could not be the sole aim - the presence of a 1x1x5 piece made me realise that the aim was to create a 3x3x3 shape filling the box and then lock them in with a crosspiece. The use of gravity to move pieces around inside adds to the fun - The Pelikan team have made the pieces with such precision that everything slides beautifully by tilting the box in whatever direction that you need.

There are 213 ways to use the pieces to make a cube so the use of the limited entry to narrow it down is crucial. There are 3 pieces with 90º corners in their shapes which very much constrain the orientation and movement once placed through the very limited entry hole. Finding the orientation of these and an order that they can be inserted without blocking each other is key to the solution here. This puzzle took me many hours and a little help from Burrtools as well. The end result is very satisfying - once the locking piece has been placed, the pieces are all locked inside. Inverting the puzzle will not let anything drop out. This is a huge challenge for any puzzler!

Grid

Grid by Lucie Pauwels

Grid is the third design by Lucie Pauwels in this release by Pelikan. It has complex pieces made from Wenge to be fitted into 5x5 grid constructed from an acrylic plate which has been beautifully frosted. We are accustomed to amazing wood from the Pelikan team but even their plastic work is perfect.

My initial approach was the usual random placement of pieces onto the grid which always progressed very nicely until I realised that I had isolated one small section of the grid and could not place a piece to fill it. Maybe starting with the more complex pieces would help? It did up to a point but then I always got trapped with a couple of pieces unplaceable. This was going to need planning - not only are there 3 complex pieces but there are also a couple of simpler pieces that have missing side voxels. My head was starting to hurt and I was on a deadline. I decided to use Burrtools to give me the position of just one piece and this was miraculous. After finding the position of just one of the complex pieces, the remainder of the assembly was wonderfully logical with literally only a few possible piece placements making the final assembly a lovely exploration. Maybe you talented puzzlers out there can solve it without help? If you can't, then making the BT file is fun and just makes the puzzle all the more satisfying.

Yoga 1

Yoga 1 by Benjamin Heidt

4 possible tetrominoes

This unbelievably complex design by Benjamin Heidt has been made by Pelikan to look incredibly beautiful using stunningly marked Leopardwood for the panels of the box and Garapa for the pieces as well as the corners of the box. Benjamin has picked 4 of the possible tetrominoes to be placed in the box which already has 4 voxels stuck in place inside and then deliberately not told us which tetrominoes he has chosen - he (and Pelikan) have obfuscated the puzzle even further by creating a hinge across each pair of dominoes and allowing the poor challenged puzzler to rotate the pieces into any of the 4 possible shapes. My goodness! This is hard enough if we were given all the correct pieces in the correct shapes to be inserted. By adding the hinges the puzzle has been made MUCH tougher! This is not for the faint-hearted.

Creating a Burrtools file for this puzzle is a challenge in itself - it will require you to know about how to use variable numbers of pieces (it is actually a great way to educate yourself into the more complex aspects of the program). Once this has been done it can be seen that there are 268 ways to insert these different combinations of these tetrominoes inside the box but only 1 is actually possible to create as a true solution. Amazingly it requires at least 1 of every type of tetromino (I'm not telling you how many of which ones). I have been working on this for many hours and have so far not managed to get anywhere at all. I suspect that I will need to go back to BT and find out how many of each piece type is required and try with that knowledge.

Minima 13

Minima XIII by Frederic Boucher

I have reviewed many Minima puzzles over the last few years. The original idea by Frederic Boucher was to fit various pieces into a 2x2x3 space through a limited opening and requiring various rotational moves which are facilitated by odd holes in the sides of the box. The series has been continued by him and also taken up by many of the best puzzle designers in the world - I have lots of them and love the variety of challenges. I now have several versions of the Minima 13 and reviewed it in June 2025 having taken 4 years to solve it. When I finally managed to review it last year, I said that this 13th challenge in the Minima series was the utter pinnacle of the series - it is quite literally the very best of them all. It takes the original premise to pack the pieces inside and adds extra stuff:

1. It is trivial to place all the pieces in the box without rotations but this is clearly not the solution because...
2. There is a single coloured voxel which must not be visible from the outside
3. Several of the pieces have been cut at odd angles to allow some rather fancy rotations.

This is a seriously tough challenge and the Aha! moments are multiple and difficult to find. I had almost no recollection of the last solve and it took me quite some time to get it again this time. The crucial moves are very well hidden.

If you own the rest of the Pelikan wooden Minima series then this is a MUST BUY. If you don't have a copy of the 13th challenge at all then this is a MUST BUY! The Minima 13 was one reason the whole series made it to my Top ten(ish) for 2025.

Minima Flop

Minima Flop by Dr Volker Latussek

Yes, we cannot have a Pelikan release without an incredible challenge from Dr Volker Latussek! This one takes the amazing Minima designs from Frederic Boucher and adds a certain Latussek flair to it. The Minima Flop has been gorgeously created using Purpleheart and Saman (also known as Monkeypod). It is simply stunning. The puzzle arrives in a specific transport configuration that Volker always designs and the initial challenge is to take the pieces out - this will give you at least an idea of the types of moves that are possible with this box and pieces. There are 4 cornered triominoes to fit into the usual 2x2x3 space. It looks like it should be a simple challenge - Volker has even given us 4 really quite large holes in 4 of the faces. One of those holes is huge but not big enough to place a piece inside on its side. Volker said this about the puzzle:

"Frederic Boucher said to me in the summer of 2024, asking if I would like to contribute a puzzle to his MINIMA SERIES. At the time, I was deeply immersed in working on my FLOP SERIES, so I suggested a MINIMA FLOP. I was confident that I would come up with something suitable despite the strict requirement of a 2x2x3 box. It quickly became clear to me that it had to be a four-piece puzzle consisting of identical pieces. The pieces could only be V-shaped. Now, the task remained of finding the right openings. And, to suit a FLOP, as many openings as possible with dimensions of 1.5x1. To my surprise, there were five of these openings, two of which I had to combine. This was the only way I could meet the requirements. MINIMA-FLOP is a nice experiment within MINIMA and FLOP. Frederic wrote to me that he had a lot of fun with it. I wish the same for you."

The name gives us a clue about part of the challenge - Minima Flop will have rotational moves like the other Flop puzzles multiple times during the solution. This gives the puzzler a few obvious things to try having some memory of what has been done before but there really isn't much space inside and as soon as one other piece has been placed, the flop move that you really want to try gets blocked almost immediately. This is time to think© and work out what is needed. The name and the simplicity of the pieces leads you astray and you need to discard your preconceptions and start from scratch. I spent a long time trying to do what I had learned in previous releases and failed before I was forced to think again. Unlike Frederic, Volker doesn't give you any useful bevels or angles on the pieces. There are no small holes in the box panels. It requires multiple rotational moves to get the pieces inside and the solution is just beautiful. 

The Cubi Series

Four amazing Cubi challenges by Frederic Boucher

There seems to be no end to Frederic Boucher's talents! Not only do we have the incredible Minima series, the Jammed series (two of which I still haven't managed to solve) as well as numerous tray packing puzzles, he also has created a series of cubic packing puzzles here that have an enormous challenge to them due to very irregularly shaped pieces, blocks attached to the inside of the boxes, as well as rotational moves. Effectively, these seem to be the combination of a Turning Interlocking Cube (TIC) at the same time as a packing puzzle. This series has been fabulously recreated by Pelikan using beautifully contrasting woods.

We have:

CUBI 12 - Ash and Wenge

CUBI 18 - Limba and American Walnut

CUBI 24 - Limba, American Walnut and Acacia

CUBI 25 - Mahogany and Zebrano

Cubi 12

Cubi 12 by Frederic Boucher

This initial slightly easier "taster" puzzle for the series consists of a box with a rotational symmetry to the interior. and four identical Wenge pieces made from 3 offset cubies. They need to be placed inside without anything protruding above the top surface (it will obviously not be completely filled when solved). I started with the 4 pieces and worked to create a cubic shape that would interlock enough to be reduced to a 3x3x3 cube. This part of the challenge was actually not that difficult. There are 58 ways to create a shape that fits in a 3x3x3 box but most of them are not symmetrical or pleasing to the eye. Searching through them to find something that would fit amongst the pieces stuck to the walls of the box was a fun exercise and quickly revealed a rather beautiful shape. Now time to place it inside the box. At this point I realised I had a problem. Burrtools will not solve this one - rotations are required. However, once I had realised this I quickly saw what was needed and managed my assembly. This is really very clever and definitely possible by any decent puzzler. I suspect the rest will be MUCH more difficult!

Cubi 18

Cubi 18 by Frederic Boucher

The second level of the Cubi series consists of 4 rather complex shapes created from cubes offset from each other. Two of them form rather fun looking staircase shapes around corners. I started initially looking at making a cube outside of the box but they were quite awkward to hold in place and I swapped quickly to trying to place the pieces into the box past the various obstructions attached to the walls. This was definitely the right approach as insertion of these large pieces takes a bit of thought and rotational ingenuity. Getting one in is easy but the second always seems to be blocked. I tried the second shape first and then the other was blocked. I was fixated on this for quite a while before exploring further. There is an alternative way to place one of them and it only got me even more confused until I went back to my initial thought. Trying the same thing again did not get me anywhere until I looked at the pieces properly. Whilst one is identical no matter which way it is inserted, the other can be reversed and whilst it looks similar now there is no blockage. My advice to you of to look at the pieces properly and experiment with everything that you can do. After inserting those, it only took a little further exploration to work out how to place the other two. The Aha! moment with this one is fabulous!

Cubi 25

Cubi 25 by Frederic Boucher

Whilst this is the 4th in the series if you take them in ascending numerical order, it probably should be the third that you try. Jakub and team have made this absolutely gorgeous from Zebrano with a Mahogany box. Again there are a number of pieces to place inside the box which has a couple of half-voxel pieces stuck to the walls. These half voxel interfere with your ability to place the in the box and also will form part of the eventual cube shape. To make it even more difficult this time, several of the pieces are made with half voxel lengths on one or more places. This will make it seriously tough to assemble the cube shape. After I failed for a while, I counted the total number of voxels on the pieces and there are 25 in all plus the 2 halves stuck on the walls (not much room to manoeuvre). I decide to try and make a cube shape outside the box with half voxel gaps in the crucial positions. I'm not very good at Soma cube puzzles and this is similar but much harder. It took me over an hour to find a cube shape - remember, the half voxel shapes make all the difference to your search. Having made my cube it was a lovely, much smaller, challenge to reassemble it in the box. Rotational moves and sliding is required. This is great fun and a wonderful next step up in difficulty!

Cubi 24

Cubi 24 by Frederic Boucher

The fourth (and final?) puzzle in this wonderful Cubi series is a really tough challenge! There are 3 beautiful grained woods. The box has a slightly limited entry due to the attachment of a 1x2x½ voxel piece across one corner. The pieces are rather complex with 2 ½ voxel pieces attached to each one. There is also a disk with smiley face on it to be added inside. This is another one where it would be best to assemble a cube outside the box and the work out how to get it inside. Burrtools won't help you as a rotation is required but it can help you search for cube assemblies. I needed this help and found 57 possible cube shapes but as soon as you adjust it to leave the 1x2x½ voxel gap, it is reduced to a single possible solution. In the interest of time, I used this to find the position of a single piece and then worked from there. It still took me quite long time to find a solution outside the box. Assembling it inside was a lovely sequence! I am sure that all you fabulous puzzlers will manage this without resorting to Burrtools.

This is an incredible release of brilliant puzzles to start off the year. There are challenges for all levels of puzzler. To me the absolute essentials are:

Minima XIII - if you have the others then this is a must buy - it's the best of the series.

Minima Flop - it's a Minima with the Latussek extra

The Cubi series - any will do but the set is incredible!