Lever Tumbler Lock

by ttsalo, published

Lever Tumbler Lock by ttsalo Jun 21, 2012


I wanted to implement a lock mechanism which is fully printable and relatively secure. The http://en.wikipedia.org/wiki/Lever_tumbler_lock seemed like the best bet.

See it in action: http://youtu.be/Fzuhta2IQZ4

The model has three tumblers with 6 bitting positions for each. It's keyed [0, 3, 5].

<b>Note!</b> The derived Fully Printable Padlock http://www.thingiverse.com/thing:27205 contains an improved version of this mechanism.

Recent Comments

view all
Might want to print thingiverse.com/thing:27205 instead, that's a more optimized and fine-tuned derivative of this thing.
looks awesome, can't wait to print it.

More from Household Supplies

view more


Liked By

view all



Lever Tumbler Lock by ttsalo is licensed under the Creative Commons - Attribution license.

Give a Shout Out

If you print this Thing and display it in public proudly give attribution by printing and displaying this tag. Print Thing Tag


Print the plate. I used ABS and 0.20 mm layer height with 200% W/T value. The plate is scaled to 150% of what the SCAD file produces, and if your printer is not well tuned, you may want to increase it even more. It's quite tiny even at that scale.

Clean up the parts. The key bitting, the bolt pin and the top surfaces of the bolt and the tumblers needed some light sanding to make them smooth, but otherwise the mechanism worked almost straight away. The key bitting is the most critical part, since if it moves the levers incorrectly, the lock won't operate.

Assemble by inserting first the bolt and then the tumblers in the correct order. The bottommost one is the one nearest the key. Check that the whole mechanism works smoothly and if not, sand or otherwise fix the binding parts. This is a technology demo right now, so there's no cover or other mounting hardware yet.

To make the lock more secure, you can just modify the bitting array in the SCAD file and you get more tumblers and the height is adjusted automatically. However, most other parameters are not so easy to adjust since the key has to operate the tumblers and the bolt in the correct order both ways. Also, the number of bitting positions per tumbler (6) is probably the maximum for this size of mechanism. Increasing that would most likely require increasing the size of the tumblers, the key and the bolt.

<p>looks awesome, can't wait to print it.</p>

<p>Might want to print http://www.thingiverse.com/thing:27205 instead, that's a more optimized and fine-tuned derivative of this thing.</p>

Fully Printable Padlock
by ttsalo