Self-locking box
Made from poplar, I saw this tricky and satisfying design on YouTube by Mr Puzzle (thank you!). The two lignum vitae knobs are only there to confuse, and in the compartments next to the mechanism I have placed large ball bearings that move around and, hopefully, create more disinformation for someone trying to open the box.
On the bottom of the box I stamped the letters 'L1' and 'R2' to give a clue that the box needs to be tilted to the left first, releasing the first wheel from the mortice, and then to the right to release the second. At each operation the lid has to be closed again very slightly to ensure that the mortice doesn't impinge on the free movement of the wheel. I also stamped '56 degrees' to indicate the amount of tilt required. Mostly people still have to be shown how to open the box, which requires no force at all.
On the bottom of the box I stamped the letters 'L1' and 'R2' to give a clue that the box needs to be tilted to the left first, releasing the first wheel from the mortice, and then to the right to release the second. At each operation the lid has to be closed again very slightly to ensure that the mortice doesn't impinge on the free movement of the wheel. I also stamped '56 degrees' to indicate the amount of tilt required. Mostly people still have to be shown how to open the box, which requires no force at all.