Uphill
Two magicians have reversed the direction of the rushing stream so that it flows uphill. This was my first GBC module....
GBC Module Catalog
The most comprehensive listing of Great Ball Contraption modules
Recently Updated Modules
Waterpark
A GBC model based on the LEGO Friends Set "Summer Fun Water Park" (41430) featuring an aquarium underneath. Due to a...
The Great Ball Race
Dragons Neck
A plain and simple conveyor. Nothing special but very reliable.
Semaphore
A semaphore indicating the ball flow: As long as balls are coming the white circle signal is up. If no more balls are...
Great Ball Counter
A counter made of 7segmentdisplays that is easy to ready. Additionally it features a gauge showing the current ball...
GBC Gumball Machine
A reservoir module themed as a gum ball machine. Additionally the output speed can be adjusted from 0 to 60 bps.
Robot Critters
Screw Up!
High Speed Pursuit
Ballkirk Wheel 2.0
GBC-O-Meter
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.