GBC Module Catalog
The most comprehensive listing of Great Ball Contraption modules
Recently Updated Modules
Two Tread Type Conveyor
This module uses two different types of conveyor belt pieces to transport balls at different angles.
Brick Mill
This module is constructed entirely from elements available in the 1980s.
Tread Lifter
Semaphore
The Ring
Clickits Conveyor
Banana Gear Screw
Robot Arm Picker
LMR Ball Pump
Screw Up with 3 lanes
Screw Up with 2 lanes
About the Great Ball Catalog
Great Ball Contraptions (GBC) modules are custom-built LEGO machines that transport small LEGO balls through creative mechanisms.
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.