I did print this very nice box.
To make the box pop open i added two neodymium magnets with the poles so that they repel each other.
This gives a spring effect and makes the box nicely pop open when you turn the key.
I used two 5 mm magnets and printed 2 holders
One is glued in the lid. The other next to the lock.
See the picture.
Happy printing , happy geocaching.
Spectrum Military Khaki Pro PLA
-Don't glue the lock to deep in the box otherwise it will not lock properly and block the keyhole.
-Be sure you are not over extruding because then the front panels will not fit.
-Better use a gel form of superglue, the very thin superglue easily creeps into places where it is not intended.