kbricks

kbricks (pronounced "kay-bricks") is a fully 3d-printable, open source construction toy. It allows for building stable mechanical models that don't fall into pieces when playing with them. kbricks parts can be printed with almost any state-of-the-art 3d printer. Start building your own model today! Popular models include a tractor, a racing car, a tipper truck, a fork lift, and many more!

Detailed printing instructions can be found on the Thingiverse platform (see link below). The videos are  serving as the construction manual for the individual models.