3D print your very own secret opening box to keep goodies and other stuff safe also you can elongate it to make a pencil case for school! I used google sketchup for this project and you can find the files in the second step.
Step 1: Designing
First i started with a cube 500mm by 500mm by 500mm and slowly measured and put in the marks for the groves where the lids would run. Sorry for not having a 3D printed model to show you how it looks but i am sure a smart DIYer like you can figure it out
Step 2: The Lid
Those are the two lids used to seal the box and keep your goodies hidden. So print off all the pieces and get ready to put it all together.
Step 3: Put Your Box Together
Once all the parts have been printed you might want to smooth with some fine grit sandpaper if your printer left a bit more plastic than needed for a smooth sliding surface and slide it all together now you have your very own secret opening box! Wait...i just told you all how it opened....um....ok your very own not so secret opening box!