Binary Counter
This GBC module counts all passing balls using mechanical flipflops (e.g. it counts using the binary system). Its...
GBC Module Catalog
The most comprehensive listing of Great Ball Contraption modules
Recently Updated Modules
Slow Scissor Stepper
This GBC module consists of a large stair run by a scissor lift that slowly lifts balls up and over. This is jtooker's...
Serpiente GBC
This is designed originally by FernandoQ. Dunes, Berthil, and NDLGBC have each made their own versions of it, this...
Cannon/Shooter v2.1
Watch This
The Mountain Pump
G.R.A.M
Barrels
This is the 2025 Brickslopes Workshop GBC by Snowy.
Hoecken
This is the 2024 Brickworld Workshop Module.
Arch Elevator
Simple GBC Train (feat. 7722)
A train module with the goal of being simple for use as a utility module. The cars compatible with the loader and...
Blue Baller
A GBC module lifting regular GBC balls together with Bionicle Spheres. The bigger blue spheres are filtered out before...
Random Module of the Day
Loading...
Latest GBC Videos
Loading latest videos...
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.