Cryptex Lock Notebook

To collect another nerdy hobby, I recently started doing some bookbinding. After tossing together a couple stab bound sketchbooks, I sought something a little more user-friendly (ie. a binding style that would open up laying flat). Fortunately, a few folks had already posted instructables on Coptic stitch bookbinding which seemed to meet my requirements:

Of course, being lazy, I wanted to improve matters find a way to create one cover that I could constantly reload with paper to avoid spending time and material on new covers every time I ran out of pages. Additionally, since my scribblings tend to be a bit subversive and my doodlings occasionally NSFW, I wanted a way to secure my notebook. Here is the result. All files may be found on Thingiverse:

The 3D printed hard cover has holes in the spine for a separate thread that secures the stitches of the text block. On the front is a circular pattern cryptex with 4^5 possible combinations. Credit where it's due, I adapted a puzzle design I saw from Kagen Sound. He does beautiful work, and I highly recommend checking out his website.

Those that just want a cover without all of the cryptex tomfoolery can head over to the thingiverse page for my earlier, non-lockable design :

Step 1: Print It All Out

Again, all STL files may be found via the following link:

Ensure that your printer has better than 200 micron accuracy in all dimensions.

Step 2: Clean Up All Parts and Assemble the Locking Key

Ensure the following:

The cover hinges freely rotate

the locking key and locking pin piece fit together

cryptex wheels are free of artifacts and elephant footing

locking pin can slide easily into its channel

Step 3: Test Fit and Finish

Slide the locking key up and down to ensure that there is no binding. Trim the locking pin when the locking key is all the way down so that it is flush with its channel. Add the discs one at a time and ensure that they can freely rotate a full 360 degrees.

Step 4: Finish

glue on the cover plate and it is complete. It's pretty impressive to fit a 3D printed combo lock in just 5.5mm if I may say so myself.

I won't go over stitching signatures to make the pages, because the two instructables linked in the intro page do such a good job. For this cover, make a text block with the following parameters:

-90mm (3.6") x 150mm (6") pages (I used the paper from a 9 x 12 sketchbook trimmed down and folded into four signatures)

-5 seams arranged 30mm apart measured from the center of the signature fold.

-12mm (1/2") thick

-awesome end paper (see photo of other notebook)

There is no specific way to stitch the text block to the cover. Anything that is neat, orderly, symmetrical, and that links the two is enough. I just looped thread behind the seams of the text block and back out through the holes in the spine.

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    2 Discussions


    3 days ago

    Looks awesome. please can you provide a video of it so we can see it in action?


    5 days ago

    Very cool idea, I like this! : )