Riddle Puzzle Box




Introduction: Riddle Puzzle Box

About: I'm a social-worker, working with 12 - 23 year-olds. I used to be a printer. In 2018 I opened a small makerspace (www.imdib.nl) in my house, where I have lasercutters, 3d-printers, Arduino's, Mindstorms and ot…

It is that time of the year again to make a cool gift. (Sinterklaas, surprise)

The gift he wanted is a survival knife. But is girlfriend has, kind of, a reputation of cutting herself with knifes while cooking. So I decided to give the knife in a safe box to keep it out of harms way.

The box is fully lasercut and has a different 6-digit code on all four sides. Only after you solved all the four riddles you can open the box and acces the knife. The riddles are printed on the top of the box.

Step 1: You Will Need


  • Acces to a lasercutter
  • (Old) paint brush
  • Wood glue
  • Rubber bands


  • 3,6 mm plywood 60 x 40 cm

Step 2: The Riddles

To make your own box, you probably want to make your own riddles.

Specially because the solution of one of the riddles is the name of the guy I'm giving this box and an other is referring to the content. (my riddles are also in Dutch :) )

To inspire you I will give you my riddles:

Riddle one:

Sliders: 0 and 1 so the answer is in binary.

Hint: The answer is the answer.

Answer: 101010 (the binary code for 42 -hitchhikers guide to the galaxy-)

Riddle two:

Sliders: . and - so the answer is in Morse code

Hint: You must be a real one for the content.

Answer: -- .- -. (MAN in morse code. There are only so many things you can do with only 6 digits in morse)

Riddle tree:

Sliders: two Letters on every slider

Hint: Login for safety.

Answer: name (The name of the guy who gets this. You can also spell the name of his girlfriend, but that won't open the box)

Riddle four:

Sliders: -> and <- arrows in different directions

Hint: This one seems logic to me.

Answer: Logic order (The arrows must be put in a logic, clock-wise order)

Step 3: Lasercutting

I added a PDF of the cutting file. The red lines are cutting lines and black is engraving. The file is editable in Adobe Illustrator.

The file is made to cut out of one sheet of 40 x 60 cm plywood on a Trotec Speedy 300 lasercutter, but would probably work as well on any other lasercutter that will take this size of material.

From the 24 rectangular holes out of the big pieces, you will get 24 bigger and 24 smaller rectangles. You will need only the bigger ones.

>>> the design is for 3,6 mm ply <<<

Step 4: Glue in the Knobs

The knobs are really easy to glue in place. They will fit exactly in the indents made by the laser engraving.

  • Put a little wood glue on the indent.
  • Push the knob in place until you feel that they sink in the indentation.
  • Put some weight on them while drying.

Step 5: Finish the Inner Compartment

When the knobs are dry, you can glue the inner compartment of the box together.

  • Hold the four walls together with the knobs on the outside and glue them in the holes in the endplate (without the text on it)
  • With the glue still wet, you can push the four walls apart to put glue in between and glue the walls together.
  • It can help to hold the walls together with a rubber band while the glue is drying.
  • Remove the excess glue with an old brush with warm water.

Step 6: Prepare the Sliders

This part was much easier than I expected. I already lasered lines on the small parts where to glue the bigger part.

  • Put glue on the two small parts. (as much within the lines as you can)
  • Push the bigger part on the smaller part within the lines.
  • Use a brush to remove the excess glue.
  • And repeat 24 times.
  • Put something heavy on it while drying.

Step 7: Finish the Sliders

Before you place the sliders you need to think if the slider has to go up or down to open the box.

If you want the slider to go up to open than you should put the U-shape part on the slider on top.

  • Sort the six sliders you are doing according to your code.
  • Put them in the holes in side board.
  • Check one more time if they are all the right way up.
  • Put the first slider you are glueing in the middle of the hole.
  • Put a little glue in the middle of the slider. (not to much)
  • Glue the tile on top, using the small line that is printed on the side board.
  • Do this for all six tiles.
  • Repeat for all four sides.
  • Put something heavy on it when it is drying.

You can see on the back that if you put the sliders in the right code there is a kind of channel for the knob to go through.

Step 8: Glue the Outer Shell

Use the inner box to glue the outer shell around. (don't glue the shell to the box!)

  • Glue the four sides together.
  • Glue the top with the text on top.
  • Use rubber bands to hold the shell together while it is drying.

If you put all the sliders in the solved position you should be able to slide the shell from the box. When only one slider is in the wrong position or in the middle the shell and box won't separate.

Step 9: All Sides

Here you can see all the finished sides!

Step 10: Finished Puzzle Box

The only thing that is left to do is (after you played with it) to put in the gift and giftwrap it to give it away.

Have fun!

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    4 weeks ago

    This is mine made from 4mm cherry veneered mdf.

    Until I master the "sticking" issue when opening i'm not sure the mdf is strong enough as it split a couple of the "[" and the bows opening. (You can see where one of the bows stripped near the top right side in one of the photos

    I was looking for a small gift idea to pop into it and found that a wee set of 4 tea light holders from IKEA fitted perfectly.


    Reply 4 weeks ago

    It looks great. Mdf is not very strong through the material thickness. I have no idea how to solve that.


    4 weeks ago

    Loved this riddle box idea, took me a couple of attempts to get a working version using 4mm veneered mdf, as I made the inner and outer boxes too tight fit, it needs a wee bit of float.

    Even after entering the correct answers I find it a wee bit difficult to open, not sure yet where the issue is, i'm guessing the sharp corners on the bows, or perhaps my accuracy when gluing the sliders in place.

    I did make a wee jig to hold the slider stop "I" and "[" in a position and then glue the slider guide in place, this helped a lot.

    Great wee project, i'll be making a few of these for gifts.


    Reply 4 weeks ago

    Glue is also my big friend and enemy at het the same time. I am curious how your version ended up looking in veneered mdf.


    3 years ago on Step 9

    Simple but effective design!
    Unfortunetly we only have 3mm or 4mm thick wood, but perhaps I can just rescale it?