Instructables

Wooden Puzzle Lock For Secret Door

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Picture of Wooden Puzzle Lock For Secret Door
The end of my pantry goes under the stairs to the second floor.  I HATE wasting valuable storage space so I decided to make good use of it by adding a wine rack.

Of course that wasn't good enough, and in true Myst fashion, decided to make a Puzzle Lock to hide a secret compartment.

I apologize for pictures only in the write-up.  I tried uploading videos of this in action, but they didn't upload.

I hope you enjoy my project.  Some parts are over the top possibly, but lots of good ideas in here I think!

- Casey
 
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Step 1: Secret Revealed!

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When the correct lever combination is set, you can now push the button in the middle of the levers causing the wine cabinet to slide backwards and reveal a hidden compartment.

Step 2: The Key is the Lock

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Of course you could just make a simple lock and have the same movement by the cabinet, but I was interested in making a lock that would challenge people to discover the correct combination.

So this is the lock design.  The 4 levers are used to prevent the middle piece of wood from moving unless all levers are set to the correct position.

When they are and the button is pushed, the middle piece of wood moves back (towards the spring).

This causes both "L" pieces to pivot and pull the wooden blocks that extend outside of the lock box inwards.  Once they move in, the cabinet underneath is able to slide back.


Step 3: How the Lock is Made pt1.

Picture of How the Lock is Made pt1.
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I took a piece of Birch Plywood and routed out L shaped grooves into the wood to create channels for the levers to slide in.

The wider grooves are 3 times wider than the wooden levers the knobs attach to.  Well…there is an exception for the bottom one…I added a twist to my locking mechanism.

I used a router for this and got the straight cuts by clamping wooden guides to the plywood to keep the router going where I wanted it to go.
Alderin5 months ago

Very cool! I love the nearly-all-woodwork approach. It is functional art, the best kind.

When it was mentioned in the comments about more combinations, and the limitations you mentioned, I had an idea for that: why not have an upper channel as well? 3 more knobs in-between the existing ones. The lock becomes a sandwich with 7 variables, of 3 or 4 positions, so over 2000 combinations. (3^7+)

Of course the downside is you don't get to see the woodwork, as all the complexity is hidden between the plywood sandwich. Not as fun to show off.

Great work!

TracRat (author)  Alderin5 months ago
That is not a bad idea about using an upper level for the knobs to get more combinations. You would definitely add complexity!

I think my woodworking was decent for this, but I was worried that if it jammed, I wanted to get to it.

I agree about not being able to look at it anymore either. I like to watch it operate.

Thanks for thinking of some options to make it better! I still have some spaces left in the house. I have some beginning ideas for the front stairs...
TracRat (author)  Alderin5 months ago
That is not a bad idea about using an upper level for the knobs to get more combinations. You would definitely add complexity!

I think my woodworking was decent for this, but I was worried that if it jammed, I wanted to get to it.

I agree about not being able to look at it anymore either. I like to watch it operate.

Thanks for thinking of some options to make it better! I still have some spaces left in the house. I have some beginning ideas for the front stairs...
evanjreds5 months ago
Holy wine rack batman! To the batcave!..... ummm batman.... I think your cave shrunk....
criggie5 months ago

Does the vibration of moving upset the wine at all?

TracRat (author)  criggie5 months ago

Not really. The commercial door closer I use is very smooth and has a 2 stage closer. I had to even set it to be a bit firm at the end of opening to make sure it struck the light switch for the compartment properly.

Th only thing you have to be careful of is when you pull the rack back forward to re-engage the lock. I was to busy trying to get a satisfying "thunk" sound when it closed and I launched a bottle from the top shelf. All the other 30 or so stayed, but this one had a slick plastic label. Oops. all it did though was break the seal and we had to drink it...

ImJopel5 months ago

Excellent!!!
Nice work! Love it! One of the better projects I've seen here in a while. Even better that it doesn't some how incorporate a frigging Arduino. I also like that you did it all with wood, which I think is a bit more challenging than using metal fab.

Only thing I might do different is, find a way to hide the grooves from showing. Actually, I'd give it more chances to be wrong too, by making more combinations possible. Maybe make the knobs plungers (Push-Pull) connected to the notched (Keyed) sliders using levers like the locking (Dead-Bolt) mechanism. Thus giving each knob three possible choices (2 wrong & 1 right) or even more, depending on how complex you choose to make it. For example, if all knobs are at rest in Middle position, your left with decision to push or pull each one. This greatly increases the chance of getting the combo wrong. But that's just my opinion.

Oh! & Nothing is over the top if it serves a purpose.
Regards...

TracRat (author)  ImJopel5 months ago

Thanks for the thoughtful comments. I did struggle with deciding if there were enough combinations with my plan. What I found was that to add more positions for each lever caused 2 problems: #1 the grooves that the levers slide in started getting large…it is tough to keep the width the size I used and not crowd the panel. The second issue is that the knobs will start to bump into each other if you make them too wide. What if one lever is all the way left and the other is all the way to the right? I used the flat disk behind the balls in order to cover the groove when they were centered. You don't see the grooves when you zero out the combination.

I added the twist to the blue knob in order to remove any guesswork. It looks like a made a typo in my write-up. you must unscrew the blue ball from the right most fork and screw it into the one to the left in order to set the blue ball properly. At any given time, the blue ball can only be moved left right or center. But in reality there are 4 spots it can move. The trim is tough to see in my picture but it definitely confused the kids for awhile. (I hid video games in there as a prize for opening the compartment.)

Oh, the distance between each spot the lever can sit is mostly determined by the width of the push bar. If I had made this thinner, then I could have fit more combinations in… but it is all a compromise because then that part of the system would be weaker…

The wood made it immensely more challenging. If I could have used some metal gears or rods, I could have made it incredibly complex. I tried to use wood everywhere but there were a few spots that were just impractical to not use metal. Like the spring or the threaded rods (which are used to create the blue knob twist).

I thought this through for a year before I started to build it. It was basically built in my mind before I started my first cut. I was very happy that I had to make very few on the fly changes to my design. It got me through a period of having a tough time sleeping at night. I would think through each step and memorize how the next piece of wood would have to move. I guess it was more than just a project for me.

Everyone's response has made this so worthwhile to share. Thank you.

jooly45 months ago

I wonder how the rest of your house looks. VERY creative...love it.

Rob3115 months ago
I like it. I hope you can see the lock itself once the door is open, it shouldn't be hidden away!
dpiccine5 months ago

Stoning fantastic!!!!

Zanaji5 months ago

THis is beautiful!

Dr.Bill5 months ago

Keeper Of The Keys.

redbeard55 months ago
this is amazing. what a clever idea. I want secret doors/spaces everywhere now.
pixelphish5 months ago

Than is so darn cool.

TracRat (author) 5 months ago

Thank you all for the encouraging comments! I am amazed with the number of views, favorites and followers. I clearly need to come up with more projects to share. You all motivate me!

If you have a chance, please vote for me in the Secret Doors and Compartments contest if you think this entry is worthy!

circuitmage5 months ago

Beautiful!

Jayefuu5 months ago

Beautiful work! Saw you on Hackaday.

geekOmat5 months ago

Loved to play Myst and definitely love this project. The idea is great and the execution is really nice.

Todd Gehris5 months ago
Wow! (wow seems good enough but the app won't let me submit without more words. :) )
21bose5 months ago

Awesome

Jobar0075 months ago

That's awesome. It takes me back...

TracRat (author) 5 months ago

LOL. I like the music idea. I do have a light that turns on when the wine rack moves all the way back. I'll have to work on the music thing...

Oracus5 months ago

Very nice! Maybe a light would turn on and a sound played when button is pushed with right combo is entered.

TracRat (author) 5 months ago

Thanks for the comments! It took about a year of thinking to figure out how to make this.

The best part, which doesn't show in the pictures, is the EXTREMELY satisfying *CLUNK* sound that it makes when the button goes in all the way and the wooden locking bars retract.

I tried putting up video of it working, but had issues with the upload. If I can figure it out, I will try to post it soon.

batonas5 months ago

Respect for the locksmith.

dwestphal15 months ago
Very nice! It most definitely is a tip of the hat to Myst, with the sliding knobs, large decorative push button release and all the clues to unlocking the door hidden in plane sight! This Instructable makes me want to create a similar locking small box! ...wheels are turning...
Great Instructable! Thanks for the post!
AussieWA5 months ago

Very impressive! Thanks so much for your 'secret door' puzzle!