A medium sized closeable box that works like my old lockbox and this video by maker's muse: 

I wanted to make a more aesthetically pleasing version as a birthday present for one of my friends. All files fit on a Prusa.

Assembly instructions:

1. place the central pin on a flat surface.
2. align the stationary disc with the central pin and slide it all the way down. The pin and stationary disc should be able to rotate independantly of each other.
3. place all 6 locking pins in the 6 radial slots of the stationary disc.
4. place the rotating disc on top of all the locking pins and the stationary disc, the rotating disc is supposed to turn together with the central pin.
5. use the fastening nut to secure the rotating disc in place and prevent any locking pins from falling out. If you hold the stationary (bottom) disc in place with your hands and twist the central pin, all 6 locking pins should now be pushed outwards. They can also be retracted by twisting the central pin in the other direction.
6. Place the fancy lid over the previously assembled parts. It should loosely fit just above the fastening nut.
7. Secure the fancy lid and the entire lid assembly in place with the “knob” by screwing it onto the last remaining thread that sticks out the top of the entire asssembly
8. Place your lid (with retracted locking pins) on top of the box body and align the locking pins in the lid of the box with the 6 radial holes in the main body of the box. There is also a wavy pattern on top of the box body that is supposed to mesh with the underside of the fancy lid to keep everything in place. Twist the central pin and extend the locking pins and your new box is ready for use!

Notes: my fancy lid unfortunately didnt print very well, I suspect the filament wasn't very good. The fancy lid also requires delicate support removal due to its intricate nature.