Jim Posted April 8, 2015 Maybe you've heard of it, maybe you haven't, a Great Ball Contraption. Seeing a GBC in action is definitely one of the most mesmerizing things LEGO can bring. Some of the contraptions are operated by a single motor, providing all kinds of movements at the same time. Our Technic Regulator and Technic Guru Blakbird has written one of the most comprehensive guides to what a GBC entails. Start your Power Functions and head over to the Technic Forum. Share this post Link to post Share on other sites
