This is a puzzle box that requires a spin to unlock. The mechanism that locks the lid in place is itself locked by eight 6mm BBs, which can be printed in place, or placed during the print.

A simple spin on a reasonably level surface allows the lid to be twisted 20 degrees, which allows the lid to be removed. However, closing and locking the box does not require any tricks; simply insert the lid and twist it to lock.

Continuing with the idea of using airsoft BBs in the locking mechanism, I designed this puzzle box from the ground up with a few ideals in mind:

• Easy to open if you know the trick, virtually impossible otherwise
• Easy to close; closing the box doesn't require performing the unlocking trick
• Aesthetically and tactually pleasing (i.e. it should look like a box but provide no clues, and it should feel solid and be fun to use)