"Mechanical Library is a open education project to inspire students to understand how the physical world is designed and made.
It includes:
A “wall of mechanisms” museum exhibit of the 36-72 most interesting and common mechanisms, such as the Universal Joint, that make our world work.
Mechanical-Library.org is the companion website. Each mechanism has a QR code that brings up the page to explain how it works, with videos, 3D printable models and augmented reality models. "