Secret Enigma Box




About: Having fun creating more or less stupid stuff

This box contains hidden mechanisms that prevents from opening it without finding clues on its faces to solve it.

At first the box only consists of four cursors that have to be positioned properly and two other cursors that cannot move, but if you look more closely you'll alo see a key hole and two strange rectangles on the sides.

To open the box you'll have to decipher it by looking at the engravings and finding some hidden parts to get new clues. Two codes are to be found in the proper order to open the box.

So far it takes ~45min to people to firgure out how to open the box

Step 1: Materials

To build this box you'll need these things :

  • 4 springs Ø5.5mm , 17.5mm long
  • 2 springs Ø6.5mm , 10mm long
  • MDF sheets 3mm thick
  • MDF sheet 6mm thick (can be replace by two cuts of a 3mm thick wood)
  • Wood glue
  • Sandpaper
  • Masking tape
  • Wood varnish
  • 1 lock + key
  • Laser cuter
  • Felt fabric (optional)
  • Epoxy glue
  • Clamps
  • Hinges
  • Wood chisel or cutter (optional, for fine tuning on sliding stuff if necessary)

This box contains all the necessary springs. They're not the exact same sizes as mine but they should work.

These clampsare a must have generally speaking when doing wood stuff.

This masking tape should work to protect wood before cutting/engraving

This adhesive felt will be perfect for the inside of the box.

Here is the epoxy glue i used.

Grab the hinges you like the most (here for example), the nailed plate shouldn't be more than 6mm long.

I used cheap wood chisels that worked nice for fine tuning here and there.

I bought the lock/key on a 0503local store because i was unable to find a suitable one online. The main requirement is that it should be equal or less than 9mm thick. Mine is 9mm thick, 40mm long, 36mm large and the deadbolt (the part that slides when turning the key) goes 8mm outside the lock (souldn't go further than 10mm without having to move the drawer). This part is clearly the trickiest if you want to build your own box. I'm thinking of a 100% lasercut lock system but for now you'll have to deal with that constraint sorry.

About the laser cuter, i own a Glowforge so the parameters i'll give will be for this specific lasercuter, but any other lasercuter will work, you'll just have to figure out the parameters by yourself. because renting a lasercuter depends on the amout of time you need it, as an indication, cutting + engraving took me around 3hours on my glowforge.

Step 2: Lasercuting Parameters

As explained before, i own a Glowforge, so the given parameters will be for this specific lasercuter.

First, i covered the MDF with masking tape to avoid burnt smudges due to the venting system of the laser cutter. Be careful not to overlap tape bands, particularly over the engraved parts as it would fade them slightly off.

The design contains 4 different engraving colors and 2 special engravings. Here are the parameters i used:

  • Red: speed=1000 - power=60 - Lines per cm=180
  • Orange: speed=1000 - power=50 - Lines per cm=180
  • Light orange: speed=1000 - power=45 - lines per cm=180
  • Yellow: speed=1000 - power=40 - lines per cm=180
  • Key shape: speed=500 - power=full - lines per cm=90
  • Grooves: speed=700 - power=full - lines per cm=90

The grooves are the engraving at the back of the top face. They're used to create "steps" on the sliders. The sliders inside the box have waves at their top matching the grooves. This way when moving the cursor they will more naturally stop at specific positions.

The key shape engraving allows for the key to be lower in the drawer and not cramp the main drawer's opening.

Cutting parameters are just the default one for "Medium Draftboard" material when cutting 3mm elements, and "Thick Draftboard" for 6mm elements.

Only cutting exception with the Felt Fabric. Mine is really thin, here are the params i used :

  • Custom material: 1mm
  • Focus height: 1mm
  • Speed: 500
  • Power: 65

I put bellow the Illustrator file with everything needed inside, from shapes to isometric views !

I also put an .SVG export of the .AI file for people that do not haveIllustrator, but please note that formatting is broken (no artboard, no dark background, et..)

Step 3: Cutting Lid Layers

Right under you'll find the 5 layers composing the lid.

Just cut and engrave them with the parameters explained on the previous step.

Only one specific action with the 5th (top) layer that has to be engraved both sides. I made it so it's perfectly simetrical which means that you can first cut/engrave one side, then flip the cut part at its exact same place and do the second side (as shown in the pictures above). To be sure the holding part don't move i added magnets to fix the MDF on the honeycomb bed.

You'll also want to smoothen the grooves with a wood chisel or the sliders might be really hard to move.

Small warning, don't throw away the center hole of the 5th layer ! It will be used as a pin holder that will act as the button to open the main drawer !

Step 4: Pro-tip : Cleaning the Masking Tape

Cleaning the masking tape can be a bit annoying because of the engravings. The most part can be removed easily but for the small parts you can use some strong tape to remove them.

Just press the tape on the small remaining parts and they should attach to the tape.

Step 5: Lid Assembly : Layer 1 + 2 + 3

Simply glue the 3 bottom layers together with wood glue.

Be as precise as possible, the more precise you are, the better it will work later !

The 3rd layer is composed of 3 main parts but also 3 small rectangles that will need to be placed precisely to avoid slider from blocking. The easiest way is to first place all the sliders in their holes, and glue the spacers inbetween as shown in the picture above.

Maintain the glued parts together with clamps and let it dry as long as your glue requires it.

Step 6: Main Drawer Assembly

Cut and engrave the 3 main parts of the drawer on a 3mm wood.
Cut the locker on a 6mm wood (or twice on a 3mm and glue both together)

Glue the 3 layers together carefully and insert the locker on the hole. No need to glue it but it costs nothing to do so.

Finally, sand the bottom of the drawer to remove the equivalent of about 0.25mm. This is very important ! The drawer's sliding hole is 3mm * 3 (9mm). If the drawer was the exact same height then it will have huge troubles sliding. That's why it's necessary to reduce its height by sanding it.

I personally added some Felt fabric on te inside of the drawer. I put the laser cutting map of it bellow as well.

Step 7: Secondary Drawer Assembly

Cut and engrave the "secondary_drawer.svg" elements on a 3mm wood.

Cut the "secondary_drawer_handler.svg" on a 6mm wood (or twice on a 3mm wood and glue them).

Glue the 2 layers of the drawer together and add the handle to it on the hole.

No need to glue the slider with four bumps to the drawer, it will attach on the side of it.

Finally, same as for the main drawer, sand the bottom of it as much as possible (but not too much !) in order to get it sliding properly later.

Step 8: Sliders

Simply cut the files below on 3mm and 6mm woods.
I added the index of the sliders as engravings to be sure not to place them in the wrong order inside the box, which would kill the possibility to solve the box.

Step 9: Placing Drawers and Sliders

Place all the sliders and drawers on the layers you assembled before.

You don't need to place the springs yet, they'll just need to be placed before adding the 4th payer.

Add the 4th layer without glue and try to make the drawers slide while pressing the 4th layer on them to make sure they will slide properly once glued. If they don't slide easily, sand their bottom a bit more.

Step 10: Adding 4th Layer

Glue the 4th layer.
Pro-tip, put the glue above the 3rd layer instead of under the 4th layer to make sure you don't add glue on places that shouldn't get glued.

As for the 3 first layers, make sure it's precisely aligned with the others !

Step 11: Main Drawer's Lockers

The main drawer has 2 locking systems related to it.

The first, and most obvious one, avoids it from opening without pressing a button.

The second is actually released when the main drawer is opened. It avoids from closing the secondary drawer before closing the main drawer.

The reason for this is that the main drawer's locking system could get damaged if the main drawer was closed after the secondary drawer.
The secondary drawer blocks the button that opens the main drawer (it's part of the enigmas), if the button is blocked, the drawer cannot be properly closed neither without forcing and potentiallybreaking it. The second lock system is there to avoid that. (i'll add a GIF explaining that better as soon as i can)

Step 12: Gluing Springs

Before enclosing the mechanisms with the last layer and the borders, use some Epoxy Glue to fix the springs to the wood.

Apply small pressure to the spring while it dries. For as long as your epoxy glue requires it.

Step 13: Adding the 5th Layer

Before gluing the 5th layer, think about adding the key locker !

Now, the trickiest part of the assembly, adding the last layer of the lid.

This can be a bit complicated as the main drawer's locking system is pushed up by springs. You'll have to manage to push it down while gluing the top layer.

My solution was to, first apply glue on the top of the fourth layer, grab a pencil, push on the spring lock with it, and slide the 5th layer around the pencil through the hole of the 5th layer. While maintaining pressure on the spring, bring the 5th layer in place and hold it in place with clamps.

Step 14: Cutting Lid Sides

Here are the sides of the lid, ready to be cut and engraved.

Be careful not to loose the front of the drawers that will be disconected from the actual sides.

Once cut, glue them to the sides of the lid.

There's only one way of gluing them properly so if you're carefull you shouldn't mix them up ;)

Step 15: Top Elements and Hint Wheels

Last thing to complete the lid is adding the elements on the top of it.

Below you'll find the laser cutting file, just glue the elements.

The small circles with symboles should be placed on the appropriate sliders according to the index shown in the image above, and in the correct orientation (same as in the image).

Finally, the small circles with a simple dash on their border should be placed inside the drawers at the places that matches their shapes.

After this, the lid should be complete and working !


Step 16: Cutting Bottom of the Box

Cut the bottom parts in a 3mm wood and glue them together.

Best way is to start with the bottom, add 3 external sides and glue them. Glue the 3 corresponding inner sides to them. Then finish by adding the last two sides to complete the box.

Add felt fabric on the inside if you wish to get something cleaner.

Step 17: Adding Hinges

Last but not least, the hinges !

MDF is very fragile and can crack easily if you try to nail it. As we need nails to fix the hinges, it's necessary to first drill hole slightly smaller than the nails before pushing the nail.

I set my hinges a bit strangly because they could avoid opening the box too much if placed this way.

Do as you want but just be careful not to hide the engravings on the side !

Step 18: Adding Some Decoration

At this point it's up to your taste and what you have at home.
I added some corners, nails and borders here and there.

I also added some varnish on the top of the box but that wasn't a so good idea in my opinion...Or i would have done better putting varnish on the other sides as well maybe.

Step 19: Tadaaaam

And your box should be complete !

There are some enhancements that can be done:

  1. The sliders can be quite hard to move.
  2. I broke the locking part of the lower box very quickly by closing the box without first pushing back the inner slider, as you'll see in the above picture i replaced it by a, not so trong, metal part for now.
  3. If closing the locker with the key before pushing back the inner slider it pushes the side out of the box
  4. The secondary drawer doesn't comes out quite enough to be able to catch the small wheels
  5. Closing the lid before pushing the back the main lock system can break the hook on the bottom part
  6. I originally put springs instead of the two manual sliders on the left but there was too much friction and we could brute force the sliders quite easily. But the design was cleaner :/.

This will be for another time :)

Hope you enjoyed !

Step 20: Solution : How to Decipher the Hints

Coming soon, i'm exhausted for now T_T

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    45 Discussions


    2 days ago

    I recently completed my laser cutter and then found this interesting box of yours. It's beautiful and well thought out. I have downloaded all the .svg files to open in Inkscape but I have difficulty in obtaining the Adobe Illustrator file, Do you possibly have it available in either a DXF or SVG format?
    Excellent Ins'tble by the way.
    My mail is :

    2 replies

    Reply 2 days ago

    Hello Alwyn !
    Thank you for your kind an appreciated comment :)

    I just added an SVG export of the AI file in the step 2. Just be aware that it's a degraded version of what the .AI provides. No artboards, no dark background, and maybe other stuff not perfect. But you should get everything needed :)


    Reply 1 day ago

    Hi Durss,
    Thanks a million for your quick response. I really appreciate it.
    It might be a "degraded" file, but it still provides the missing info needed for the full engraving on the top.
    Keep up this interesting and mind blowing designs. I'll be watching.
    Greetings from Dark Africa.


    Question 21 days ago

    Hi Durss, really like your design! I have collected all the materials to start this project, however when I download the SVG file for the top (layer 5) there doesn't seem to be
    any layers/lines for the engraving design, only the perimeter cuts, and cuts within the
    perimeter. The other SVG files with engraving layers/lines are fine. I have to open in Inkscape, save as DXF, and open in RDworks for laser cutting. Do you know if this will only open correctly using Adobe Illustrator. Any suggestions as to what I may be doing wrong
    would be greatly appreciated.
    Thanks, Rick

    2 answers

    Answer 20 days ago

    Hello Rick !
    Good catch ! It's all my fault no worries.
    I just fixed it you can download it again ;)

    Can't wait to see how things go for you ! If you have any question/issue don't hesitate to ask for my help !
    You would be the first to build something i've shared on Instructable and i'm pretty excited about this :D
    The main thing i would advise is not to bother with the grooves on the back of the top layer and remove the "waves" from the 4 sliders. They're supposed to work together to create "steps" when moving the sliders but it doesn't work well and it can be pretty hard to move the sliders more than anything... I haven't found a solution to this problem yet :(

    BTW i quite changed the design of this box since this article. I mainly removed the locker for something 100% laser cut with some gears, and something that blocks the key hole until everything is solved. But i'm still not 100% satisfied so i haven't shared anything yet ^^
    I attached pictures of it if you're curious ;)

    I realize i still haven't explained how to solve the box.. I'll do that as soon as i have some time :)

    Anyways, best of luck for your build ! Can't wait to see the result :D


    Reply 20 days ago

    Hi Durss,
    You are amazing, files downloaded perfectly! Thanks soo much! I am excited to start this project. Thanks for the tips about the sliders. Your 100% laser version looks great. I am also collecting the items to build your 'Password Protected Sketchbook' and looking forward to starting to build after I complete the 'Enigma Box'. Will definitely share once I finish. Thanks again, your the best!


    2 months ago

    V-v-v-voted! And favorited. And commented. And shared. This is literally awesome, I want it.

    2 replies

    Reply 2 months ago

    Thank you. Your comment/voting/fav are very appreciated :D


    Reply 2 months ago

    This ‘Ible is very appreciated. That’s why it’s featured.


    2 months ago

    Hi Durss (from France ;-) ) , this is really awesome. Voted for you for the contest. Favorited also and determined to try to build one. Thank you for sharing all the details.
    I don't have a laser cutter, I will see if it's reasonnable or not with commercial web services.

    I love that kind of puzzle box (rather than the japanese kind). Built one with an arduino for a birthday.
    I found and backed one on KS (long time ago now and didn't received it for now but I was among last ones...) : the codex silenda. looks amazing! hope to receive it soon.

    1 reply

    Reply 2 months ago

    ooh indeed i forgot about this book that seemd pretty nice !
    I backed this plastic box that i also have been waiting for an eternity... i'm still not sure if 'ill ever receive it :

    In paris it's around 30€/30min. I also had to buy a darn 300€ class the first time i used a lasercuter on a fablab (just to teach how to use illustrator, i was quite pissed off...). That's how i made my first instructable project.
    Having my own lasercuter made this project possible otherwise it would have cost something like 600€ just for the lasercuter rent i think. Also, "real" laser cuter are a pain in the ass to use... :/

    Can't wait to see yours if you build it :D


    2 months ago on Introduction

    Totally ready to give this a shot over the holidays. I've got 3mm MDF, a Glowforge and most of the bits on hand. Except the lock...any more details on what store / supplier you found for the lock? Or do you have one of THOSE hardware stores near you?

    1 reply

    Reply 2 months ago

    There's a big store in paris calle BHV where we can find loooads of different things. I found the lock here (for 15€...). I had to saw a part of it btw so it fits in the 9mm height.

    I searched on Amazon (france) but couldn't find a single suitable lock.
    There's this on aliexpress that might be suitable after some trimming :
    You'd just ahve to review the box design so it fits the shape of this specific lock.

    But to me, my design with this "real" keylock is flawed. We can litterally break the box by simply closing it if we don't think about pushing a bar inside the box before that :/. I'm thinking of a new design with a full wooden lock system so it's easier to make adn that wouldn't break the box if not used in the right order :)

    I also want the key hole to be closed by another system until the second symbol sequence is found.
    Right now we find the key at maybe 30% of the resolution time, we use it right away and forget about it. I don't like this. I'd prefer if we used it only at the end as the LAST step for opening the box :D

    I don't know when nor if i'll succeed doing this, but i hope i will :D


    2 months ago

    Another way to get in to this type of project is by building Japanese Puzzle Boxes. There are websites on these and venders that laser cut out the patterns. Then, your need directions, glue and some patience, but totally doable. Has the kits
    Then you need to find Bruce Viney's plans....right now the links on BH website does not seem to work. But some of the kits come with free plans.
    Check them out.

    1 reply

    Reply 2 months ago

    I own a similar kind of box (a himitsu bako)

    I like this kind of boxes but to me it lacks some thinking. Im a Myst/Riven kid and i loooooOOooove having to look and understand clues in order to know how to solve a box. More than just random manipulations to more or less understand the inner mechanics of it. I haven't found much boxes like these so far :/
    The only one i actually know is this crowdfunding i've been waiting to receive for too long (if i ever receive it..) :

    If you know some i'd love to get links !! :D

    Thank you very much for sharing !!


    2 months ago

    Wow!!! Amazing. Well done. You obviously have way to much time and money on your hands. Thanks for documenting & sharing.

    What took longer building the box or documenting the ibl.?

    15 seconds to carefully pull the hinge pins and I'm in ;-))