Locking mechanism multi-coded

thingiverse

You'll need the following parts to put it together: one base, one cover, three pins (you can get those in steel), three slide rings (sun rings work too), and three lock rings. Insert the pin into the lock ring according to your unique coding system. Next, attach both the slide rings to the base, securing them with more slide rings. Do this entire process three times for a total of nine slides - it's a pretty standard design, really, so you can modify it all you want!