GBC Module Catalog

Great Ball Contraptions (GBC) are intricate LEGO machines that transport small balls through creative mechanisms and modules.

This catalog is the world’s most comprehensive resource for GBC modules, featuring hundreds of modules from dozens of builders, a lot of them with build instructions. Whether you’re a seasoned builder or just discovering the hobby, you’ll find hundreds of unique designs to explore and build.

Start browsing to discover the amazing variety and ingenuity of the global GBC community.