Lego bricks can be used to create complex and fascinating mechanical marvels, as demonstrated in this YouTube video that showcases the assembly of 20 different kinds of linkages and other mechanisms using Lego bricks.
The video features a variety of linkages, including a Schmidt coupling, universal joint, torque limiter, and constant-mesh gearbox. Each mechanism is shown operating on its own in a close-up shot. The linkages are then connected together to create a larger mechanism that is both mesmerizing and useless.
The video description includes a link to the kit used to create the contraption, as well as building instructions.
