Fully 3D Printed Code Lock




Introduction: Fully 3D Printed Code Lock

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 must be possible to fully 3D-print a code lock. It is probably been done before, but this is my take on it. I wanted to do it with a small amount of parts.

I ended up using just 5 parts for a three digit code lock. For every digit more you will need to add just one part.

This code lock is made as a proof of concept. I really like to play with it and hold it in my hand. It makes a really annoying chirping sound when I turn the dials. I like the sounds, my colleagues hate it :)
You could use it to lock a chest or something, but it won't really keep burglars out or something.

You don't need any skills for this project. As long as you can operate a 3D-printer, you are good to go.

Step 1: You Will Need

For this project you will need:
  • a 3D printer
  • enough filament 

And that is pretty much it. You also need a computer with the right software but if you can read this and you have a 3D-printer I am pretty sure you have one.

When you want to paint it and age it or something, you will need paints and stuff. But that is totally up to you.

Step 2: Print the Parts

Download the designs

You download the 3D-designs from here: http://www.123dapp.com/Project/Fully-printed-code-lock/2311097
I use 123D design to draw the parts.

Print the parts

Print all the parts from the 123dapp site. The round part, you will need to print 3 times.

Step 3: Put the Lock Together

Put the parts together
  1. Push one of the dials on the socket plate
  2. Push the next dial on the first one
  3. Push the third dial on the second one
Finished! (or not?)

When all the dials are in line, you can put the latch in now. When you turn the dials, the lock is locked.
You can only take the latch out again when you put all three dials in the right position.

Step 4: Painting

You can leave the lock in the color you printed it in or.... you can paint it. I painted it!
  • Take the lock apart again
  • First de-grease the parts
  • Spray on a sealer for plastics (to help the next layer adhere)
  • Watch paint dry
  • Spray on a primer
  • Watch paint dry
  • Spray on the color you like
  • Watch paint dry
  • Use a sharpy to ad markings (you can use numbers, letters or anything you like)
  • If you like you can weather the end result (there are loads of instructables on how to do that)

Step 5: Finnish!

Put the lock back together again
  • Put a little bit of petroleum jelly on the ends of the dials
  • Push the parts together again like before
  • Choose something to lock


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    8 years ago on Introduction

    Fantastic! Simple, yet effective!


    8 years ago

    Doesn't the pet jelly make the chirping go away? I would think of this more as a reusable anti tamper seal. A container could be sealed and reopened several times by the proper persons, if the seal is discovered broken, you know unauthorized persons have gained access.


    Reply 8 years ago on Introduction

    Yes the petroleum jelly killed the sound. I just printed out a new one for the sound :)

    It would definitely work as a seal on the cookie jar :)


    Reply 8 years ago on Introduction

    Cookie jar, that thermostat someone keeps changing, office supply locker... Have lots of fun tormenting your coworkers.