Well I was looking for puzzles on the internet, and I happened to cross this puzzle : http://www.kagenschaefer.com/DiamondBox.html
, which brought me to this page: http://www.kagenschaefer.com/Book2.html
It looked very cool and I wanted to make it for my sketchbook but I didnt see anything on how it worked or anything on how to build it. I thought about it and how it could open and lock for a few minutes until I found out how. This is just a prototype, it isn't my regular sketchbook, just the one that I usually carry around instead of my bulky one.
It is made of cardstock and cardboard glued together, it is very strong and durable and it is being used in my next project(just a hint, it uses my old NXT)
I don't know if the creator would like me showing how to make it(He sells the wooden box one), so I just posted a photo instructable for now, I don't see any copyright or a creative commons license so I think it would be fine if I just credit the person for inspiring me to make this, if anyone knows if I can't, please comment!