Last year at LEGO World Utrecht, BrickNerd challenged several builders to create a new GBC module only using parts from a single set. After the success of that competition and the following interest, we are bringing the challenge back for another round! The builders loved it, the crowd loved it, and it pushed all of us to be more creative. So here we are back again with a new set that has entered the arena…
Choosing the Right Set for a One-Week GBC Build
Choosing the right set was the first real hurdle. Last year, the choice was easy. 42167 Technic Garbage Truck had plenty of panels and just enough gears to build a reliable GBC module, so it was the obvious pick for the first attempt.
For this year, we again leaned into Technic sets. They simply offer the best starting point for GBC building, with the structural parts and mechanical elements you need to achieve smooth, consistent ball flow.
My picks for this year were the following sets:
42168 John Deere 9700 Forage Harvester
42209 Volvo L120 Electric Wheel Loader
Let’s go over all of them and see why they made it to the list:
John Deere 9700 Forage Harvester – $39.99
This harvester set was one of the contenders last year and has by far the most gears in its price range, which is great when you want to build some more complex mechanisms. It also includes good parts for building a small and compact GBC module. The one downside of this set is the lack of large panels that would make it easier to close off sections or guide the balls in a clean way. You can work around it, but it does limit how neatly you can finish certain parts of the module.
Ford Bronco SUV – $64.99
This Ford Bronco set looks nice, but it is not the strongest option for a GBC module. It has a good amount of beams and connectors, so building a solid frame is no problem. The downside is that it barely includes any large gears, and the few that are there are mostly used for simple steering. For a GBC module, that lack of gears quickly becomes a limitation. You can make something basic with it, but anything more advanced will be difficult without extra gearing options.
Volvo L120 Electric Wheel Loader – $119.99
This loader is interesting because it offers a bit more mechanical variety than the Bronco. It includes about the same number of gears as the John Deere set and some useful lift parts that could inspire a different type of motion. The wheels are less helpful for a GBC, but the core Technic structure is solid. Overall, it could be the basis for a more complex module with some cool techniques, but the price tag is quite high and less accessible to new builders.
Tipping Dump Truck – $49.99
The dump truck is a fun set with a simple mechanism that could translate into a GBC movement. It includes a handful of small gears—enough to drive a basic mechanism or a simple lift. The tipping bed itself could be adapted into a ball-moving feature. The drawback is that the set is fairly small and lacks many advanced parts. It is workable, but building something smooth and reliable would take some creativity.
Our Pick for the 2025 GBC Challenge
After some discussion, the decision was made to use the John Deere Forage Harvester! The number of gears, the accessible price tag, and the challenge of working with a limited part selection made it the best fit for this year’s build.
There was serious consideration to go with the Volvo L120 Electric Wheel Loader, but given we only have one week to build a GBC module during the event, time becomes a real limitation. Building a module from a set of around 1,000 pieces in just one week is not feasible, especially of you are trying to use all of those pieces. (It might be a cool challenge for next year, though!)
LEGO World 2025
Just like last year, we planned to host this challenge again at LEGO World Utrecht. It is the largest LEGO event in the Netherlands, bringing together nearly all Dutch-speaking GBC builders. As a result, you will meet a highly diverse group of people. The atmosphere is lively and dynamic, with creative builders from around the world, each bringing their own style and ideas to this challenge.
All builders in the GBC loop (we forgot to take a group picture so this picture is from 2024)
This year we had the same builders as last year, so I will give a short introduction to each person so you know their background in each team.
Team one
From LEFT to RIGHT BERthil, Philip and Kris
Team one consisted of various GBC builders with different styles:
Kris Bollen from Belgium is known for bringing reliable modules. He has a very inventive and creative approach to designing GBC mechanisms. Kris often starts by looking at the parts he already has and then builds a module around them, which can lead to very unique and unexpected designs.
With more than nine years of GBC experience, Berthil van Beek from the Netherlands is a builder who creates highly advanced mechanical modules. His work is often considered a form of mechanical art, combining precision and creativity in a way that stands out within the GBC community.
Philip Verbeek from the Netherlands comes from a very different background. He specializes in designing modules from existing LEGO sets, which is exactly what this challenge is about. Online he is also known as PV Productions.
Finally, I, Noah de Lange from the Netherlands, was also part of Team One. My style focuses on polished GBC modules where I pay just as much attention to the appearance as to the mechanical function. I also enjoy incorporating storytelling into my builds, adding an extra layer of personality to the module.
team two
Team Two is full of experience with the following team members:
Just like last year, Petter travelled all the way from Norway to join LEGO World Utrecht, where he is known online as Rokreder. Although he is not yet widely known within the GBC community, he brings a distinct style and approach to module design. Communication within the team was effortless, since Petter speaks fluent Dutch, so there was no need to switch to Norwegian.
Team Two also featured Ben Jonkman from the Netherlands, who has a lot of experience and is the oldest participant in the entire layout. Ben brought a deep well of knowledge in running layouts.
Completing this strong lineup was Maico Arts from the Netherlands, a true veteran with more than seventeen years of experience. Maico is widely regarded as the European GOAT of the GBC community, known for his exceptional skill in designing modules and his ability to oversee large, complex layouts with impressive precision.
Competition Rules
It would not be a complete contest without rules, so for this competition every module had to follow the standard GBC guidelines. Each team also needed to ensure that their module was fully running in the loop by the end of the event.
Summary of the GBC Standard designed by NOAH DE LANGE and Fredrik Hareide
Once finished, the modules would be evaluated by a diverse panel of judges, ranging from Star Wars builders to people with no LEGO background at all. Additionally, each module should be able to accept a Power Functions or Powered Up motor, making it versatile for builders who would like to use the set to build a GBC module.
Design Journey – Team One
From the start, we knew we wanted to use the set’s large number of gears. That led us to brainstorm a wide range of different lift mechanisms. In the early stages, we like to prototype quickly, testing many designs and ideas to see what’s possible. After that, we narrowed things down based on what was most feasible.
As we were exploring different ideas, Kris immediately connected the gears in the set with something he had recently built:
“The month before, I had created a module with a planetary gear. And since I saw several gears lined up on the harvester’s box, that became my first idea. The rest of the team immediately started working with it.”
At the same time, Philip was also thinking about how to make the most of the unusually large number of gears:
“So many gears in this LEGO set… but what to do with them? On the first two days (out of six), we brainstormed with the team on various options and mechanisms. Seeing and feeling the parts in front of us gave us many good ideas, but only one idea stuck with us until the end. We really wanted to use as many gears as possible, and I think we succeeded. The tricky design challenge for this GBC was to get the GBC balls on top of the lift mechanism in a reliable way. This turned out to be more difficult than expected, given the limited part count.”
On the second evening of the event, we developed this lift design. Even though it later proved to be a real challenge, we really liked the motion of the ball, so we decided to continue with the idea.
first iteration of the mechanism
During the event, a judge stopped by and mentioned that he really liked the curved fender piece. He also said he hoped to see a creative use of that part in our GBC module. On the second day, Berthil, Philip and I were fully focused on building the module, completely serious and concentrated. Meanwhile, Kris was quietly working on something entirely different…
Gif of diffrent expressions of RAAF
“While the team was busy building the first prototype, a jury member stopped by and mentioned that the fender piece was very important to him. That made me think: how can I give this part a different purpose? And that’s how Raaf was created.”
After a few beers and a lot of laughter, Kris suddenly introduced us to a new character named Raaf. None of us really remember why we chose that name, but it immediately felt right. Raaf became an unexpected source of entertainment for the rest of the evening.
Built from a small collection of LEGO parts, Raaf turned out to be surprisingly expressive. The green fender pieces created perfect, exaggerated eyebrows, and the yellow gears formed a pair of wonderfully confused eyes. We even came up with a signature sound for him, a puzzled “HUHN,” which quickly became an inside joke.
Before long, Raaf had become such a highlight that we created our own WhatsApp stickers of him. What started as a spontaneous build ended up becoming one of the most memorable moments of the entire event.
Last year, we noticed that the crowd really enjoys it when you build a new module right in front of them. Getting people involved in the design process is a great way to start conversations and connect with visitors. They can watch the entire process live and stay around to see how you create something from scratch or how you iterate a prototype into a final design. It shows how much work and effort go into building these models.
Kris building and testing the module at the Event
After a lot of rebuilds and adjustments, and after scraping a ton of pieces off RAAF to make the module more stable, we finally reached the point where everything came together.
”We also experimented with many different agitators until we tried to use the whip element. Very unusual, but it turned out to be perfect. We went through many variations until we landed on this final design.”
On the final day we could add the module to the loop and do some testing and last improvements before letting it run.
Design Journey – Team Two
I wasn’t part of this team’s build, so I’ll let Maico take the spotlight. After all, who better than him to tell the story of their design journey?
Maico: This year, Noah once again arrived with two Technic sets. The 42168 John Deere Harvester. Quite a few gears, one straight panel, and the rest were all curved variants. Hmm. That could turn out to be a challenge.
The other team had already managed to create a somewhat complex mechanism. But why not go for a simpler mechanism instead? The question was: which one? The previous year we had used a stepper. So I didn’t want that again. At one point, I slid the six yellow gears onto a long axle. Hey, that actually looks like a drum. With a few pins on it, you could easily scoop up the balls.
on the right philip building for team one and on the right maico building his module for team two
That’s how the roller with two pins was quickly born. Next came the inbox. With a good number of beams available, that idea came together quickly as well.
Then the jury came by. One judge said: “Those fenders are a nice part.” The other added: “And there also needs to be a return loop.” Hmm, another challenge… But that was solved quickly enough by using the wheels as extensions of the legs, which also conveniently incorporated the fenders.
module with return ramp
The return loop became the next challenge. Now, that in itself isn’t a problem; it’s simply a second track that leads from the output back to the inbox. The real challenge was switching between a stand-alone module and one that could be used directly in a circuit. The module’s output was made flexible by allowing it to fold downward. On the inbox side, the wall was raised with a few panels. These can rotate. So by swinging the panel open, the balls can roll back again.
Meanwhile, we still needed to secure the middle pin on the roller. Otherwise it wouldn’t last long. A solution was found using the rack gear.
The seat got its place as well, everything was fitted with lighting, and even the little whisk-like pieces, which in the original model act as corn guides, found a new place. but now, back to Noah.
Noah: Altogether, the module was done before the end of the event, and also ended up in the loop in time!
The Two Finished Models
Here are the final videos and building instructions for both models, so you can purchase the set and build both models yourself. Last year’s model was built by others many times following our instructions, so it is truly amazing to see how the community has embraced it.
Building Instructions for Raaf!
Building Instructions for Forage Harvester C-model
Building Instructions for Forage Harvester C-model (with return ramp)
Our main goal is simply to have fun during the event and sharing our design process, so seeing others enjoy and build our designs really means a lot. If you decide to build them, please share your version with us. We would love to see it.
And The Winner Is…
GBC SET COMPETITION CUP
The built trophy cup for the winner will soon be updated with the latest results! Who will walk away with GBC glory? After a long discussion, the judges reached their final decision. Twan briefly tells about the judging.
Judging Report
Judging Report for 2025’s GBC Set Competition Cup: A diverse range of jury members were appointed. This included not only people from the GBC community itself, but also a variety of outsiders. From terrain builder to vehicle builder, and from LEGO Masters to people completely new to the LEGO community.
The points the jury considered were overall appeal, creativity, ball flow, element use, and bonus points for surprises. Team Two first presented to the jury. Their lengthy presentation almost resulted in points being deducted, but it was a testament to the builders’ enthusiasm and passion for their contraption.
A classic sweep function ensured efficient and reliable throughput of the little round plastic balls. Its similarity to the original John Deere tractor set was seen as an advantage by some members of the jury, while others viewed it as an opportunity for greater creativity. Still, the fact that this produced a highly durable machine was universally praised.
Both teams present there modules for the judges!
The feature that allowed the unit to be reconfigured into a re-looping Rube Goldberg-style machine mesmerized the jury. This satisfying transformation feature was bound to make people who build it from the instructions happy. Overall, the jury was very impressed with what this team was able to make from this small retail Technic tractor set.
It was then up to Team One to convince the jury that their build could meet or surpass the high standards set by Team Two.
Tense look on us competitors to see what the judges think of our modules
The immediate chuckles from jury members seeing the comical direction the second team took made it obvious that it was not going to be an easy choice. The use of the gear train as a sort of arm lifting the balls seemed an excellent and creative use of the yellow parts included in the John Deere tractor set.
In addition, the use of the full parts assortment to create a crow-like face fit the farm theme of the original set very well. One member of the jury noted that in an earlier version they preferred that the crow’s nose was more functionally integrated in the full design.
It was a shame that this feature was not kept. The build seemed to score a tiny bit lower on reliability though, as there was a dead zone where a plastic sphere could escape its GBC fate. To the jury’s delight, the build also included a re-looping bypass feature that caused balls to be whipped back into the crow’s feet again. The jury was sure that any builder recreating this contraption would have a great time as well. This was not going to be an easy decision. Within the jury there were clear preferences for each build. It took negotiation and the famous Dutch tendency to seek compromise to point out a winner based on the judging criteria.
Ultimately for the 2025 GBC Cup, the jury selected Team One’s Raff! module as the winning build. The jury noted that although they had to choose a winner, they were sure that builders would be delighted to build both creations at home. It was a close call, and the jury looks forward to next year; we are sure the competition will be even more exciting!
RAAF module with the GBC CUP!
Looking to Next Year
And with that, the winner is Raaf! What makes this challenge special isn’t just the final modules—it is the shared experience of designing them live. Both teams proved again that when you build under constraints, in public, and with a clock running, the creativity that emerges is something spectators rarely get to see, let alone builders. Even with the small Technic set, these builders’ imaginations were huge with what they could do with it.
With Raaf taking home the 2025 GBC Set Competition Cup, the trophy gets another well-earned update. And the free instructions are the real reward for the community. If this year is any indication, the 2026 challenge is going to raise the bar again—new parts, new ideas, new surprises, and undoubtedly a few moments of delightful chaos.
Thanks for following along, and we can’t wait to share the next design adventure with you. Until then… keep those balls moving.
What set do you think would make for a good GBC module? Let us know in the comments section below!
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