During the creation process of different type of Armor, especially the one from Iron Man. I did realize that no one seem to include hinge system or anything about the articulation parts for the knees and elbows.

I've design that Flat Hinge that allow you to place it in very thin space. Also the hinge got 2 long plate that can be mold exactly to the parts that you want to connect just by warming-up the PLA and placing it while it's hot!

I've made more than 12 at this day and keep working well.

https://www.youtube.com/watch?v=mG3RBeHAI1I