Neil's Puzzle Building Blog
19Dec/110

Melting Block

Melting Block is a fun little packing puzzle designed by Tom O'Beirne. I was fortunate enough to get one of Tom Lensch's special copies when he made a small run of these puzzles recently. Originally made in the 1970's it's great to see that this puzzle is so popular with a number of people still making it and it still being well received.

Melting Block.  That Ebony block has to fit there?

Melting Block. That Ebony block has to fit there?

The puzzle is a nine piece packing puzzle, plus the box. Some of the versions which have been made have a lid which fits on the box and may have a space for the 'extra' piece, however the version I have from Tom doesn't. The puzzle measures 4.5" x 3.25" x 2" and each of the pieces in my copy is made from a different wood, including the box, making this version really stand out.

Each of the pieces is etched with the wood type

Each of the pieces is etched with the wood type

Each of the pieces has been engraved with the name of the species of wood which is a great touch (and a nice reference if you're still getting to grips with identifying the woods). The box is made from Lyptus, and the pieces are Purpleheart, Canarywood, Holly, Bubinga, Yellowheart, Indian Rosewood, Ebony, Pink Ivory and Makore.

When the puzzle was sent to me, the first eight pieces were neatly packed in the box with one small piece wrapped separately. As you can see from the first photograph, the box is looking pretty packed even before you try to find space for that extra piece. Of course this is exactly why it's called the melting block.

There really is space!

There really is space!

I spent around half an hour working on this puzzle, trying to figure out how I could re-arrange the eight blocks which were already packed into the box to make room for that ninth block. On initial attempts, I could find space for around half of that block, so I got all nine blocks into the box, with half a block sticking out. Not perfect, but it certainly gave me hope that there was more space to be found. When I found the combination that created the extra space, it really put a smile on my face, to see the ebony block slip into place perfectly.

Solving this one really needs you to use all the available space, and once the last block drops into place, you realise there really was a huge amount of free space when the blocks were first in the box, and now it's truly full!

This is a great puzzle to pass around as it's not going to get damaged and will really make you think. My son has had a good few attempts at solving it, but so far he's not succeeded, however I expect he'll solve it at some point when he comes back to it. The copy from Tom really is stunning, and the fit and finish is perfect, as you'd expect from a master woodworker like Tom.

If you're interested, some of my fellow bloggers have reviewed some of the other versions out there. Head over to Allard's blog to see what he had to say about the copy he bought from Wil Strijbos, Brian's blog of the Creative Crafthouse version called Redstone Block, and finally Kevin's blog to see what he has to say about it.

Overall, we've all enjoyed this puzzle, and I highly recommend you pick up a copy for yourself. You'll not be disappointed! If you'd like a copy, Creative Crafthouse have their version available for a very reasonable price.

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17Dec/110

Tromino Trails

This entry is part 5 of 6 in the series IPP 31

Carrying on with my review of IPP31 puzzles, here's another of the puzzles that I picked up when I was at the recent Post IPP California Puzzle Party. Tromino Trails was Stan Isaacs exchange puzzle from IPP31, and given that Stan was the host of the Puzzle party, it would have been rude not to buy one of his puzzles.

Tromino Trails

Tromino Trails

Tromino trails is designed by Donald Knuth and made by Pavels Puzzles. You can read Pavel's description about the puzzle by following the link, and also purchase a copy for yourself if you'd like one. And I highly recommend you do!

This puzzle goes back to 2009, and IPP29 in San Francisco. There Donald Knuth gave a talk about varying puzzles he was working on and passed out a sheet with some puzzle problems that people could play with later. One of those problems was the Tromino Trails problem. I'll let you read about it on Pavel's site, as he was there and will explain it far better than I.

However I digress.The Tromino Trails puzzle is a physical version of Don's paper problem from IPP29. The puzzle consists of 24 L shaped trominoes with varying paths marked on them, a tray that can be configured to a number of different sizes and five challenges.

The first problem, a 6x6 loop

The first problem, a 6x6 loop

You start off with a 6x6 square, and 12 pieces, with the goal being to fit the pieces into the tray and form an unbroken loop with the trail marked on the pieces. There's a single unique solution to the problem. Given that the tiles are transparent, the trail is visible on both sides, and therefor can be flipped over and rotated as desired.

The 6x8 challenge and pieces marked with one dot.

The 6x8 challenge and pieces marked with one dot.

You then move a few bars around and get a larger 6x8 tray, add four marked pieces, and have the same goal of an unbroken loop. Again this problem has a unique solution.

Reconfiguring the tray to the next size

Reconfiguring the tray to the next size

Moving the tray around is easy as the spacers all have tabs on their ends that fit into notches in the tray and have a number of dots based on the challenge you're attempting. A great idea and really well thought out.

Next up a 6x9 tray created by moving more black frame pieces, and two new trominoes. Same goal, same unique solution ... are you seeing a pattern yet?

All five challenges, add progressively more pieces, and a bigger tray until you're using all 24 trominoes, all with unique solutions, and you have a beautiful, and elegant puzzle design. I think the nicest thing about this (given that we know I'm not good at tray packing puzzles) is that this one is really approachable. I've been able to solve all five problems, and none of them are too difficult. Yes they're a challenge, but not such that you get frustrated and want to throw the puzzle across the room.

There's no solutions provided, but if you are stuck, or just curious, then click the 6x6 solution link or the 6x8 solution link to see the solutions. After that you're on your own. After all, what's the point in my giving you the solution. This is actually a fun tray puzzle!



16Dec/110

Tubular Burr

The Tubular Burr is a 3D printed puzzle, created by a good friend of mine Derek Bosch. The goal of the puzzle is simple. Remove the two black pieces from the cylinder and put them back. Derek kindly gave me this version when I gave him a copy of the Involute puzzle by Stewart Coffin I made recently.

Tubular Burr by Derek Bosch

Tubular Burr by Derek Bosch

Measuring 1.5" tall x 1.75" diameter it's a good sized puzzle, and as you can see from the photos, having the puzzle dyed with different coloured pieces from the cylinder really makes the puzzle pop. The White Strong and Flexible material really stands up well in the puzzle, and despite the model being hollow, there's no worry about anything breaking.

Inside the cylinder are a couple of notches, and both pieces are also notched. These notches all interact with one another inside the cylinder to make for a fairly tricky puzzle. Don't be put off by the fact that this is a 3 piece puzzle. I'll attest to it not being easy to solve. (See my later comments on that!) It total it takes 14 moves to re-assemble the puzzle so it's a good challenge.

Tubular Burr Open

Tubular Burr Open

Tubular Burr IPP Entry

Tubular Burr IPP Entry

Derek originally created this for IPP29 in San Francisco as his design puzzle entry, where it was created from sheets of laser cut acrylic which were glued together. He also used it as his Exchange party puzzle that year too. The puzzles for the IPP were created from a clear blue acrylic, however the first time I was able to play with this puzzle was with Derek's prototype "Darth Vader" version which is made from solid black acrylic. If I'm honest, I love this clear version, and can only imagine that it makes things even more infuriating as you can see everything that's going on inside the cylinder! Truly an excellent puzzle as nothing is hidden.


Darth Vader Prototype

Darth Vader Prototype

Darth Vader Prototype pieces

Darth Vader Prototype pieces


Derek first gave me this puzzle to play with one morning at work, and I took the pieces apart and placed all three pieces back on his desk. He told me that wasn't good enough, put it back to the way it was when he handed it to me. When I first played with the puzzle it took me around 5 minutes to take the pieces out of the cylinder, and less than a minute to put the pieces back in. When I handed it back to Derek less than a minute after he'd told me to put it back, he was astonished. I had put it back together far faster than anyone else had, and generally, he notes that it's much harder to put the pieces back in than it is to remove them.

I can confirm that having played around with the copy Derek gave me, I've not repeated this incredibly fast re-assembly, and in fact the second attempt took me a good 20 minutes to put the pieces back in! (going back to the Involute I gave him, he's still not taken it apart in over 2 months, so I think on average I'm still up - or rather Stewart Coffin is!)

Going back and resolving it several times now, it still takes me on average 5-10 minutes to put it back together, so perhaps my first attempt was beginners luck! I am getting quicker as I remember the solution but I get the feeling that leave this for a few months and come back to it and you'll still find it a challenge every time.

This is a great little puzzle, and is well worth picking up a copy if you weren't lucky enough to be part of the IPP exchange. Visit Derek's Shapeways Shop to pick one up, or one of his Maze Cubes. They're offered both dyed and undyed, and while frustrating me that I didn't solve it as quickly the second time, it proves that it's not a simple puzzle, and well worth owning.



15Dec/111

Houdini’s Torture Cell

This entry is part 4 of 6 in the series IPP 31

Carrying on in the IPP series, today I'm looking at Mr Puzzle's IPP31 exchange puzzle "Houdini's Torture Cell". I was lucky enough to be given this one as a gift from my fiancée for my birthday, after dropping a few hints. Mr Puzzle (Brian Young) is great at making sure that his exchange puzzles are relevant to the location of that year's IPP, and this is no exception. The puzzle celebrates Harry Houdini’s first public performance of The Torture Cell at the Circus Busch in Berlin on 12th September 1912. A small copy of the original poster from that show is printed on the presentation card as you can see below.

Houdini's Torture Cell

Houdini's Torture Cell

As the info card states, the object of the puzzle is to free Houdini from the torture cell. For those not familiar, during this illusion, Harry Houdini was suspended by his feet, locked through the top of the box which was filled with water, and escaped without drowning. Now having performed this illusion myself many years ago while I was still doing magic, I can confirm that there was no steel ball in the bottom of the tank, however the puzzle does recreate nicely the shape of a suspended figure, with no apparent way to escape.

The puzzle is very well made, as with all of Brian's puzzles. The puzzle makes use of the wood and perspex together to create a very sharp looking puzzle. On the bottom of the puzzle you'll find the Mr Puzzle Logo branded into the wood. Despite the very visible screws, there's no screw driver required to solve the puzzle, so you can stop thinking along those lines! At just under 4" tall, and a little under 2" square at the base, this is a good sized puzzle, and feels good in your hands when you're working on it. Not too small that it's fiddly.

If you're a seasoned puzzler, you'll be tempted to get the compass out for this puzzle, as Brian states that there's lots of magnets, but no "tapping" required to solve the puzzle. You'll find a very strong magnet in the base, and a couple of others elsewhere. The question is what to do with them.

On the Mr Puzzle website, Brian states that the idea for Houdini's Torture Cell came from one of the locks in the incredibly complex "The Opening Bat" puzzle. Brian felt the idea was unique and very satisfying to solve so he revisited the idea and changed it to present in a way that would suit IPP; this way it's available for lots more people to experience a great 'Ah Ha' moment.

Houdini safely out of the cell

Houdini safely out of the cell

And the Ah Ha moment in this puzzle is excellent. The beauty of the puzzle is that everything is on show for you, so really you can; after a quick investigation; think about how to solve the puzzle and then go ahead and solve it. Well, when I say everything, I mean almost everything is on show for you. There's a little bit of discovery required, and you'll need to find a tool or two hidden in the puzzle to help you solve it, but everything you need is right there in front of you. If you really get stuck there is a solution provided in a folded piece of paper, so if you don't want hints, don't unfold that paper.

Balancing the Ball on the base is easier than it looks

Balancing the Ball on the base is easier than it looks

The puzzle's party piece as I think of it is that once you've figured out how to solve it, you can leave it sitting on the shelf with the metal ball balanced on the podium at the bottom of the puzzle. Trust me, there's no way you're going to be able to get it there with dexterity alone, and leaving it in this state not only makes it look great on display, but also makes people wonder how on earth you got it there.

I highly recommend this to any and all. It's a brilliant little puzzle, and solving it is a lot of fun. I have to agree with Brian's thoughts, that this is a very satisfying puzzle to solve, and I'm really glad he decided to make this version of the puzzle as it's unlikely I'll get the chance to play with an Opening Bat. With Christmas coming up, this would make a great gift for the puzzler in your life. To see what other people think of it, read Allard's review and Oli's review for another perspective.



14Dec/113

Check Me Out

This entry is part 3 of 6 in the series IPP 31

Quite some time ago now, I mentioned in the post about the Post IPP California Puzzle Party that I'd purchased a copy of Dave Rosetti's exchange puzzle from IPP31 and that I'd write a review soon. It seems that soon wasn't very soon at all and it's taken me months to get round to writing it! But here at last is the review of 'Check Me Out' designed by Stewart Coffin, and numbered 256 in his numbering system.

STC #256 - Check me out

STC #256 - Check me out

Check Me Out is another devious tray packing puzzle from Mr Coffin, where a mere four pieces have to be packed into the tray. To make things interesting, the tray isn't square, it's a nice parallelogram, and one piece is conveniently not placed in the tray. If that wasn't hard enough, the card which comes with the puzzle kindly states


"With puzzle art such fun to play
Chuck the four "checkers" in the tray
So that shape and color both will be
In perfect two-fold symmetry
"

Front of the info card

Front of the info card

Back of the info card

Back of the info card


The Puzzle itself is fairly plain. There's no exotic woods used here (possibly Maple for the lighter wood), and the base of the tray is made from a veneered 3 ply plywood. That said, the grain in the veneer of the base of the tray is nice enough and gives a good contrasting colour to the pieces. Add to that the fact that the grain is offset to the angle of the walls of the tray really helps to mess with your head as you're solving it. The bottom of the tray is marked in pencil "256 STC 2011".

Bottom of the tray

Bottom of the tray

Each of the four pieces is very accurately cut and has had the corners rounded very slightly to take the sharp edges away. It's a small detail, but as a fellow puzzle maker pointed out to me when I started making puzzles, it really does make the puzzle far nicer in the hands when you're solving it.

Solving this one really took quite a while for me. I spent several hours trying to find a combination where all four pieces could fit in, ignoring the symmetry part of the problem. This is an excellent puzzle that will likely keep you busy for a long time. Who would have known that four pieces could provide such a problem to placing them in a tray?

I'm not going to post the solution here, as that would spoil the fun. If you're really stuck, then drop me a note and I might help you out by letting you know where one or two of the pieces go!



13Dec/110

Sputnik

It's time for another Vinco puzzle review, and this time we have another puzzle that's not a co-ordinate motion puzzle. Yes Vinco does make them, and he has a fairly good range available. Sputnik is a beautifully shaped six piece puzzle where the object is to take the pieces apart, then re-assemble them into the space faring shape. Thanks to Puzzle Master for sending me this puzzle to review.

Vinco's Sputnik

Vinco's Sputnik

It almost goes without saying that this is another beautifully made and finished puzzle from Vinco. There really are few other people out there making puzzles at this quality for this price. The woods used have been waxed so the natural colour and grain is preserved, making for a great looking puzzle which will stand out, especially given the unique shape of this puzzle.

One thing I will note in this puzzle is that in order for the pieces to come together the way they are intended, there is a small gap between a couple of the blocks in each of the six puzzle pieces, and while it doesn't detract from the puzzle at all, and you'll not notice it in the solution shape, it does make solving the puzzle slightly easier, as you can use the gaps to tell where the pieces are joined into halves, before combining the halves into the final shape.

One of the two halves of the puzzle

One of the two halves of the puzzle

One of the challenges with this puzzle is that the way each of the six pieces are combined is not intuitive. Given that all six pieces are identical, it's hard to see how you join the pieces to create a shape that will interlock into the UFO like solution.

Six identical pieces

Six identical pieces

This is another excellent puzzle from Vinco, and I highly recommend it. If you're not a fan of co-ordinate motion puzzles, this will give you a good challenge, and no need to worry about growing a third hand to hold the pieces in place as you assemble it.