First Puzzle Box

So, December 2016 rolls around, and once again I find myself significantly lacking in both money and ideas for a Christmas present for my daughter, Isis. That usually means that I will end up making her something; which she will have little or no use for, but will keep it anyway because it came from me and was made with love (and because you can't return hand made gifts to the store- lol).

One of her favorite Christmas presents of recent memory was the year that I created a scavenger hunt type game for her. I hid about 25 or 30 small boxes in three different houses, each holding a little cash, or a small gift and a clue leading to the next box. It took her about eight hours, with her boyfriend helping, to find all the boxes. It was a lot of fun for both of us, but I always thought the puzzles she had to solve to find the next boxes were a little too easy. Of course she was only 17 or 18, and couldn't even drive yet, so I was a little limited. Also, she has a tendency to give up if things don't come easily to her; so I soft balled it a little bit.

Around the beginning of the month, I saw a YouTube video by Benno Baatsen showing off a puzzle box that he had created. I got the idea to buy the plans for the box from his website so I could build it for Isis' Christmas present, and inside I could hide some cash too. Then I got the idea to not tell her how to open it, and put a clue in it also. Then I could expand on the gift later, when I had a little more time and money, by putting another gift at a destination designated by her "clue". This plan buys me time- however long as it takes her to solve the clue to get to the next part. And this time, I would make the puzzles challenging- starting with the initial puzzle box.

The original puzzle box design I wanted to build required 42 moves to open. However, I ran into some issues with the construction and didn't think it was going to work out. So at the last minute (literally, like two days before Christmas), I decided to change to a completely different design, which I felt that I understood much better, and seemed like it would be easier to make (and probably to open as well).

I originally intended to make a prototype out of MDF and cheap wood scraps to work out all the kinks, and then make a final version out of nice wood. But of course I ran out of time, so the prototype ended up being the final version. The main body of the box is made from reclaimed 3/4" MDF and the mechanical parts are made from 1/4" hardboard and Luan scraps. By the time I got the main part of the box done, I realized that I would have to use the prototype as the final product, so I did use nice hardwoods for the decorative outer trim. I cut my own 3/4" edge molding from Chakte Kok (redhart), which was used along all the edges of the box, and I cut large disks of Spalted Maple for the face decorations.

Here is how it all went down-
Step 1- Cut six perfectly square pieces of MDF for the side panels. Then bevel all the edges at 45 degrees.

 Step 2- Glue the square panels together at the mitered faces to form a box. The box needs to be in two halves, three panels per half- in a "U" shape.

 When the two halves are slid together, they should form a cube, and if you are lucky, friction will hold it together and the seams will barely be visible.

Step 3- Drill a hole in the center face of one of the halves. You will need a round plug that fits into this hole and is the same length as the thickness of the face. I used a 1-3/8" forstner bit to drill the hole and a length of 1-3/8" oak dowel to fit into it. This is where the inside lock mechanism connects to the outside of the box.

 Step 4- Now for the internal locking mechanism. I won't go into excessive detail about the locking mechanism, mostly because the person who designed this box sells the plans on his website, and it would be pretty shitty of me to purchase them and then spoon feed them to all of you for free. The clever among you can probably piece enough of the design together from these pics that you wouldn't need to see the plans in more detail, but if you are interested in building one of these boxes, I recommend you buy the plans for yourself. They are just a couple of bucks.

 I cut the tumbler slots a little too wide, so I had to shim them with a cut down Popsicle stick.

 Here they are all shimmed up and with the tumblers in place. I made the tumblers from chopped up pieces of a large nail.

The locking mechanism is built in two layers- the tumblers, and the latch arm.

 I reinforced my latch arm with a bent piece of steel (a nail) due to the fact that the sides are made from heavy MDF and the latch arm is only a thin piece of luan.

 I epoxied the nail to the luan and ground the ends to match the shape and length of the latch arms.

The latch arms hook onto the receivers (one on each side), which I made from bent metal tabs. I had to countersink them into a mortise. This is one area where I strayed a bit from the published plans. 

I also put some paper shims under the stops that dictate the rotation of the latch arms. This was to provide clearance so there would be less friction and would hopefully prevent binding in the mechanism.

On the inside of the lower half, I pasted a special message for my daughter.

Step 5- Now onto the outside of the box. The original plans call for corner bosses to add strength and help hide how the box halves slide together. I decided to put molding along all the edges instead. The molding was hand made simple square corner molding which I made from some Redhart I got from the hardwood lumber place down in Amish Country. This 32x4.5 inch board cost me $19.

I'm not very good at making mitered corners, but I think these came out fairly well. I was very careful and crept up on the cut. Only once did I cut a little too much and had a loose sloppy fit, and I ended up remaking that piece. 

 You have to be careful where you apply your glue, especially on the side pieces. Make sure to only glue the molding to one face, so the adjacent face can slide away when the box opens.

  Chakte Kok is a beautiful red color, but I have heard that it will fade to brown fairly quickly (within an hour if left in sunlight). Now my entire shop is covered in fine bright red/pink sawdust!

 Each of the faces will receive a decorative piece, one of which is connected to the oak dowel that turns the locking mechanism. I found this nice thin panel of Spalted Maple and cut six disks out of it. I cut them on the bandsaw and smoothed out the shape with a disk sander.

(Why, yes, that IS my new ShopSmith Mark V with home made disk sander attachment. Thank you for asking!)

 I used thick CA glue to attach the five disks that are purely decorative. The sixth one, that opens the lock, I attached with epoxy.

Step 6- Finish up with some sanding and a coat of shellac. I would have given it a more substantial finish than a single coat of shellac, but it was literally 3pm on Christmas Day by the time I was finished, and I had been working on it for over 24 hours straight. A quick coat of shellac was all I could manage.

 This was my very first time making a puzzle box. It probably took me about 36 hours total. There was a bit of a learning curve. I'm sure a second one would go faster. I did enjoy this project. It was very satisfying once it was finished. I would have liked to have been able to show it off to a couple of people before giving it away.

I think this design lends itself well to modification and adornment. The trim and faces could easily be decorated in just about any style or motif. Definitely look for some Cthulhu themed boxes of this type in the near future!

UPDATE (10/03/2017):
Well, it took ten months, and she had to resort to reading this blog to figure it out, but my daughter finally got the box open! So now she can get started on solving the clue to the second stage which was hidden inside. Muhahahaha!