Calibron 12 Puzzle Project
Well that year sure did fly by fast…another Christmas, and another wooden puzzle for my bro. Frustratingly I didn’t actually manage to get into my garage at any other time this year, so this Christmas’ puzzle gave me a good excuse.
However, as always time was against me I needed something fast to make yet difficult to solve. I did my usual internet research, and came up with a few possibilities, but eventually settled on a puzzle from 1931 which had been invented by the youngest son of the famous Thomas Edison, a man named Theodore Edison. Much more information about this puzzle can be found at this website. However if you just want the basics, the puzzle is essentially a set of 12 rectangular blocks, each of very specific sizes. The idea is to arrange all of the blocks together such that they form a larger rectangle, with no gaps whatsoever. Apparently there is only 1 possible solution…well it suited my needs perfectly.
As usual I started by designing the puzzle in 3D. However this was probably the first time I have created a project where this may not actually have been completely necessary since the design was so simple.
I created the shapes in Maya first so I could get the measurements correct
Once I had done this all I needed to do was to print the shapes out onto a piece of paper which I would use as a cutting guide. Next I started to look for materials. I found a board of ash which was left over from the Cot Project and decided to use that as it was just the right size and already thinned down and thicknessed.
I started with a single planed board for this project
The board was quite thin and roughly consistent thickness
All I needed to do to the board was to smooth it down a little with my smoothing plane to get a really glossy surface.
I smoothed it with a smoothing plane
Next I cut out the paper shapes from the print-out and glued them to the board with a glue stick.
I used a glue stick to stick the printed shapes to the board
And then took this over to the band saw to rough-cut the shapes out ready for more accurate shaping later.
and cut them roughly on the band saw
The next stage was to get the shapes as close to the lines as possible and keeping the angles at perfect 90 degrees on all corners…not as easy as it sounds. I used a combination of hand planing and sanding to achieve this.
I then used the plane to get the shapes to exactly the right size
And I also used my belt sander to help with this task
All of the rectangular shapes cut
All that remained was to sand off the paper cutting templates and smooth the pieces a little. This was easily done on the belt sander again.
I used the belt sander to remove the paper and glue
So essentially this was the end of the project! This had to be some kind of world record. However I wanted to put the pieces in a box of some kind. My first though had been to buy a cardboard box and try to age it somehow thereby making the puzzle appear to resemble the original puzzle. However someone in work suggested that I should make the box from wood…and although this would mean a bit more work…I secretly liked the idea of spending more time on the project, so I agreed with his suggestion and decided to make a wooden box too.
The first step was to select material. Because I’d used such a light coloured material for the puzzle I wanted the box to contrast it strongly and decided to use a dark wood. After a little foraging in my garage I found some old mahogany strips which I’d salvaged from our old back door when we had it replaced a few years earlier and decided to cut them down and make the box out of it.
I had some salvaged strips of mahogany left over from a door we removed when we bought our house
Step 1 was to cut it into usable sections which had not holes or cracks. Because these had been outside for quite a long time, some of the wood was just not usable but I managed to get enough usable material from them to make the box.
The strips were a bit rough and had some nail holes so I cut them down into usable pieces
All of the rough cut sections for the box
I used the belt sander to clean up the sections
The pieces looked very nice when they were sanded and smooth
Once all the sections were cut and sanded I cut 4 pieces at a long enough length to accommodate all of the puzzle pieces once the box would be created. I also cut 45 degree edges using the compound mitre saw to allow for a square box.
I used my compound mitre saw and a stop block to cut the sides of the box
The cut sides
I tested the sides to make sure they were cut accurately
With the sides cut I used my new framing clamp to hold them together while the glue set.
I used my new framing clamp to hold the sides together while gluing
Next I started work on the top and bottom. For this I needed to edge join two lots of three pieces together to create boards large enough to cover the box. Therefore I needed to flatten the edges of the pieces and I did this by clamping them together in the vice and running my jointing plane over them. Then I glued and clamped them overnight.
I needed to create 2 larger sections for the top and bottom so had to edge joint pieces together
I planed them flat together
and then glued them and clamped them overnight
Once the glue had dried I simply had to clean up the boards a little on the sander and then cut them to rough size on the band saw.
With the glue dried they look a bit messy…
…but nothing a little sanding won’t cure!
The sanded top and bottom
I rough cut them to size on the band saw again
The bottom section was carefully sanded to the right size and I slid it, with glue, into the box and again clamped it overnight. The whole box was then sanded together to remove any glue residue and clean it up in general.
And did some minor tough-up on the belt sander to get a very close fit
With the bottom glued in the box I sanded the entire box together
For the lid I needed to create a rebate along all of its edges to allow it to sit in the box snugly. I used my router table to do this and took small amounts of material off at a time until the box was a nice tight fit.
The lid needed a small rebate to allow it to sit inside the box which I cut on the router table
Here you can see the rebate
This is the finished box
And here it is with the lid on
All that remained was a general clean up with sand paper and to select a finish
The whole box had a good sanding with a piece of sand paper to make it nice and smooth
Here you can see the box with the pieces inside
I decided to use shellac to finish the box as it has no real odor and looks really nice. I tried it out on a small off-cut first to make sure I liked it before applying it to the whole box.
I decided to use shellac to finish the box. I tested it out on a off-cut first. You can see the effect it had
I applied the finish with a rag
And once it was dried I gave it a very light sanding. Here is the finished box
And that was pretty much it! Here are some pictures of the completed puzzle with an instruction leaflet that I created to accompany it.
Here is the completed puzzle
This is how the puzzle appears when all enclosed in the box
I made an insert with information and instructions which would fit inside the box
Completed puzzle
On Christmas day my brother seemed to like the puzzle and I later heard that it had him stumped pretty much the entire next two days. Eventually he solved it though and sent me a picture of the completed puzzle. I think it took him about 2 days in the end, so that’s probably the longest its taken him to solve any of my puzzles so far…which is good…just got to make an even harder one next year 🙂