It has never been easier to build a complete Great Ball Contraption (GBC) loop yourself! GBC 31 features a flexible and elegant conveyor and can be used as a self contained loop and participate in a GBC layout. Using a more accessible LEGO Set and focusing on one single mechanism this GBC is by far one of the best GBCs to get started.
This GBC is entirely built using only parts from the LEGO Tracked Loader and can be referred to as model C of the 42094. This GBC makes sure you master the GBC building techniques and tricks so that you eventually also can build your own GBCs. By default the whole machine is powered by hand but it can easily be upgraded with any LEGO motor (more information in the building instructions).
The GBC 31 Flex Conveyor puts all control in your hands! Adjust speed, height, slope, input and output! Altogether, this smooth running module is a perfect GBC to get started in GBC building! Learn about gearing, gearboxes, speeds (rpm), clever lever systems and more.
The GBC Balls go up on the long conveyor belt after which they are being dropped in a catch tray. By default this catch tray guides the balls back to the beginning of the module so the ball flow never ends. However we includes an ingenious lever system which adds the possibility to simply convert the catch tray and guide the balls to the output (on to the next module).
By default this module is powered by hand. A small drive handle in the middle can be rotated to power the conveyor belt. The lever in the middle controls the speed of the input drive. Pushing it all the way in slows down the system while pulling the lever out you gain more speed. By rotating the most left handle you can control the height and slope of the conveyor belt.
Fun Fact
Although we had a pretty clear idea of all the functions we could include it was a real challenge to incorporate them using only the parts of the LEGO set. From a design standpoint we also wanted to have all the control handles on one side so it’s easier to adjust and play with it. This is part of the build and play experience we always take great care for.
Building Instructions Preview
Try before you buy. We completely understand. See the building instructions previews on the left or try one of our free building instructions.
Upgrade your GBC 31 Flex Conveyor
In the building instructions is explained how to easily upgrade the GBC 31 Flex Conveyor with various parts.
Power & Automate
How cool is that!
Learn more!
Get the accessories
We have GBC Balls, handy electronics products and fun accessories available. Take a look at all our accessories!
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Nicole Walker –
This was our first GBC module too, my son (age 11) and I (mom) were so excited to be able to build something so cool! The instructions are absolutely fantastic, so thorough and easy to read step-by-step. The attention to detail is remarkable, every piece and function is accounted for and works exactly as shown in the video. We will definitely be purchasing more instructions from PV-Productions! Just have to buy more Lego first.. and make more space in our playroom :)
colin49brown –
My first ever GBC and I enjoyed making it very much. My only complaint it that I completed it too quickly, so now I want another!