This is a spring loaded box I made. It takes a little tinkering, but worry not, once assembled it is very reliable.
You will need:
The assembly is pretty stright-forward, but I do recommend to pass a drill bit through were the hinge will pass to get a smooth action.
Enjoy!
Disclamer: I designed the box, but added STLs I found to make it so much cooler. If anyone recognises their work, please comment so I can give you propper credit!
The author marked this model as their own original creation.