A LEGO Great Ball Contraption (GBC for short) is a machine that passes LEGO soccer balls or basketballs through a series of complex modules – sort of like a Rube Goldberg machine. They require a good deal of planning and engineering skills, and are an interesting challenge for LEGO fans who would like to experiment with something more complex. 🙂
There are many excellent examples of Great Ball Contraptions on YouTube, however you will soon discover that most of them are very large, and require an immense number of parts. This may discourage LEGO fans to even try building a GBC. However if you examine them closely, you will see that all GBCs are made up of smaller modules. Each module handles the balls in their own unique way, then passes them on to the next module. So it is quite possible to build Great Ball Contraptions module by module, as your skill, experience, and LEGO collection grows (all images by Josh DaVid).
In fact, you can build single-module GBCs, that feed the balls back to themselves, and thus creating a closed loop within a small space. Because these small GBCs don’t require so many parts, but are still fully functional, they are a great way to experiment with GBC building ideas. You don’t even need LEGO Power Functions elements to operate a small GBC, instead, you can make them manual. Once you build a couple of modules that you are satisfied with, you can open up and connect the loops to create a larger GBC, and even add Power Functions.
To help you start out with small, sell-containing GBC modules, LEGO fan Josh DaVid created a series of examples and tutorials that you might use for inspiration. Josh also demonstrates how each module can be operated by hand, or attached to a LEGO Power Functions motor. I also like the tasteful designs and color-schemes.
The basic idea of Great Ball Contraptions is to keep the balls moving, and as you can see in the videos above, there are many ways to roll, lift, throw, and guide balls through a path, and you can use LEGO elements in pretty much unlimited ways to create the action. As long as the piece can roll, push, flip, or drop the balls, they can be incorporated in your layout. While here our focus is on smaller modules, Josh also has a series of tutorials on larger units with more detailed instructions on his YouTube channel.
If you plan eventually to connect smaller GBC modules, it is a good idea to build them in a compatible way, so you can easily open the loops and pass the balls from one module to another. While you can certainly establish your own system for connecting modules, you might also want to familiarize yourself with the Great Ball Contraption Standard, established by LEGO fans to be able to connect smaller units from different builders at LEGO shows and conventions. This way your modules are ready to play well with those built by others from the start.
Great Ball Contraptions are an excellent way to take the LEGO hobby to a more challenging level, while still having lots of fun. And as demonstrated here, you can start small, and build up your modules, as your skill level and experience grows. What do you think? Have you considered building your own GBC modules? Or did you make one already? Feel free to share your own experiences and tips in the comment section below! 😉
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