Having put all the pieces of the puzzle together, the next task was to play with it. I wanted something that provided a challenge, but was also solvable. No sense in having something that is too difficult, or has issues with the mechanism. My first attempt to put things together, I didn’t use the locking mechanism I had designed. I wanted to see that things went together and had a good feel to it.

In putting the puzzle together for the first time, I realised fairly quickly that some of the longer pieces I had created were less than solid when made from Lego. My older Lego bricks do much better than newer bricks. It seems that the newer Lego is made from a softer plastic and doesn’t hold together as well. Remember as a kid using your teeth to separate bricks? Well that’s not a problem on new bricks!

With a little bit of care, I was able to put the puzzle together , and it did form the cube I had intended. I will be honest though, I wasn’t entirely happy with the result. There were a couple of the sides which I felt weren’t as good as they should have been now that I could see them and watch how they interacted, so I played around, and redesigned two sides to make things work better.

On my second attempt, I had the same issue as the first time, that the Lego really doesn’t hold together too well. I’m sure I could have made the pieces larger to get more stability from the Lego, but I didn’t want a puzzle that was too large. As it stands, the puzzle is about 4.5″ cubed. It’s a nice size to work with, and doesn’t use every single brick I have lying in my spares box to make it.

So with a little care and a careful hand (along with a jig I made out of blocks to support the pieces as I moved them into position in the solution) I got the cube together. This time I was much happier with the fit, and the way the puzzle pieces interacted with each other. There is a good amount of sliding the pieces together as they interact with each other, preventing a simple push together solution.

The image below shows part of the internals of the cube as I put it together. Each of the pieces here has to be slid into place, and the moved up/down etc to reach its final place in the cube. For someone not familiar with this sort of puzzle, it could be a challenge to see how things will fit in the solved cube.

At this point I was fairly happy, but there was no way anyone else could ‘play’ with the cube. It was too fragile, and the pieces came apart under their own weight, not to mention with someone tugging on them. At this point, there was little other option but to glue the bricks together. So with some suitable glue in hand, and my diagrams beside me to make sure things went back together correctly, I disassembled, glued and re-assembled the sides before leaving things to dry overnight.

Coming back in the morning, the pieces were solid and I could put a good amount of force on the previously weak points without any breaks or problems in the pieces. In an ideal world I would rather not have had to glue things, but at least Lego is cheaper than the Livecubes, and also easier to get, so not a huge loss.

With the prototype complete, time to give it to someone to test …

Well all the work is completed in Burr Tools. I now have a fully working puzzle, and a proven assembly and disassembly. That’s all very well, but the virtual world really doesn’t let you know how a puzzle feels to work with, or to manipulate. So for that I needed to create a prototype.

There are a number of tools out there designed for the job. Livecube is one such tool, and given that all the blocks are perfectly square, it makes the job of creating a burr puzzle very easy. The drawback to Livecube is that it’s not easily available, and if you want to be able to seriously test your design, or be able to hand it to someone that doesn’t know the mechanism, then you need to glue the pieces together. In my mind that makes things a little more expensive that I’d like for a prototype, that I don’t know if I’m going to like.

As it happens, I have a huge Lego collection. So I decided to use that. As anyone who is familiar with Lego will tell you, Lego bricks are not perfect cubes. It you take a 2×2 brick, and put it side on to another 2×2 you’ll see that it’s not as high as it is wide. Fortunately it’s easily fixed as you can think of the brick as being 5 units wide by 3 units high. Each flat plate is 1 unit high, so one brick plus two plates gives you a cube.

With that in mind I started building the pieces using the model I created in Burr Tools as my reference.

About an hour later, I had all the pieces made, and it was time to sit down and solve the puzzle…

As I mentioned in my previous post, I planned to discuss the steps I went through in creating my first puzzle.  This is going to be a burr puzzle, with a twist.  Rather than being able to see the pieces, they will be contained inside a cube.  In reality, the walls of the cube will be attached to the pieces, so that the completed puzzle will form a cube rather than putting the pieces into a cube.  Don’t worry, it will make sense as I go!

The first of those steps was to get some sort of idea of how the puzzle would look, what the pieces were going to be, and to verify that it would actually work as a puzzle.  I drew a few paper sketches and had the idea in my mind as to what I wanted.  From there I was introduced to Burr Tools.  Check out the links on the right for more on the tool.  It’s an excellent program and allowed me to create a virtual prototype of the puzzle, and verify that everything would would the way I intended it to.

Now, I’m not going to pretend that this is fool proof.  You need to work with the program as it has some limitations, and you really need to understand the mechanics of your puzzle to be able to get the program to do what you need.

The image below shows just one of the sides that I created.  As you can see, both the internals, and the external side are there, and the top left shows all the pieces I created.  I spent a lot of time working with the program to make sure that the pieces held each other in place and didn’t just fall out when the puzzle was assembled.

The one thing I wanted to do was have the final piece (in my original idea, that was the piece shown below) to work like a key, which you would turn once inserted which would lock the entire puzzle in place.  Burr Tools doesn’t have the facility to deal with rotations, however I could still use it to check this would work.

As it turns out,I didn’t use this feature for the first version of the puzzle, as it is possible to build it without, and my prototyping material (Lego) doesn’t make that rotation easy.  In wood, I could curve the ends so that they would turn past each other, but without a lot of work that ‘s not possible in Lego. 

I ended up with two distinct versions created in Burr Tools.  The first was a non-rotation version, and the second followed my original plan and retains the turning key to finish.

With the virtual puzzle complete, next step was to make it into something I could handle and check how it worked.  There are a number of tools out there to do that, and you can even export the shapes from Burr Tools and upload them to a site like shapeways for 3D Laser printing if you want.  I’ll talk more about that in the next post though.

For now, as you can see from the image above, Burr Tools gives you nice easy to follow cubed units to allow you to translate the design into whatever prototype you’re going to make.

So I’ve been toying with the idea of creating a few puzzles of my own for some time now.  I love Japanese puzzle boxes, and have a couple in my collection.  I also love wooden puzzles, probably because I like the feeling of wood.  There’s something about the way wood feels when you work with it, and no two puzzles made from wood will ever be the same thanks to the grain and so on.

Anyway I digress.  I’m not a wood worker, and have limited experience working with wood so I know that I have no chance currently at making any sort of worthwhile Japanese puzzle box.  However I was asked just before Christmas to make a pencil case for my girlfriend.  So I got some wood, dusted off the tools and got to it.

Now at this point I had virtually no power tools, so everything was done by hand.  The wood was marked up, and sawn using a hand saw, I added dowels which I made just using a hand drill, and mitered the bottom to place the base in using my Dremel. 

Ok, so why is all of this relevant?  Well having completed this simple project, I realised that in fact I’m not all that bad at this, and maybe I can start doing something a little better.  So what now?

One of my friends is also a puzzle designer, and I really like the things he’s done.  He creates burr puzzles, and variants of burrs, and that seemed like a sensible place to start.  After all, in its simplest form, a burr puzzle is just lots of cubes stuck together.  Well my friend pointed me to a great software program called ‘Burr Tools’.  It allows you to not only create the pieces for your puzzle, but it can also solve it for you.  Well I wasn’t interested in solving puzzles I owned, but in creating my own.  I had an idea for a puzzle cube, where the burr would be internal and unseen and set about creating it.

The next few posts will follow the creation of that first puzzle from it’s initial idea, through modelling in Burr Tools, to my first prototype and then hopefully the first finished version created in wood.  Keep checking back to see the progress!