It has never been easier to build a complete Great Ball Contraption (GBC) loop yourself! GBC 20 features a mesmerizing module which covers a full loop so the ball flow never ends. Using a more accessible LEGO Set and focusing on one single mechanism this GBC is by far the best GBC to get started.
This GBC is entirely built using only parts from the LEGO Mine Loader and can be referred to as model C of the 42049. This GBC makes sure you master the GBC building techniques and tricks so that you eventually also can build your own GBCs. The whole machine is powered by hand on default but can easily be upgraded with any LEGO motor (more information in the building instructions).
Master gearing & mechanisms
Learn about the wonderful world of mechanisms by building our GBC 20. The star of the show is by far the cardan gear mechanism which acts as a lift for the GBC Balls. The cart of the mechanism holds up to 2 balls and get filled by triggering another timings mechanism at the bottom. When filled up the arm of the cardan gear works it’s way up and drops them at it’s highest point. The balls will be catched and return to the base via the return path. By doing so the loop will never end.
Fun Fact
Designing a GBC from such small part inventory really took all the ingenuity and experience we gathered over the years. Parts are being used in a new way and many problems had to be solved for getting this GBC to work and making it sturdy and reliable. Using over 98% of the parts that come with the set we really did get the best and most out of the original LEGO 42049 set. There was a real challenge to build a GBC from such a small set but we succeeded again.
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 20 Mining Lift
In the building instructions is explained how to easily upgrade the GBC 20 Mining Lift 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!
The GBC 20 Mining Lift all over the world
Upload today & Check all other Fan Builds
dsesteran –
Very interesting building, details can be only understanding buildling it. Very fun.
joopmelchers –
Nice GBC, Only needs some finetuning in the end.
Leuke GBC, ben nog bezig om hem goed werkend te krijgen.
paweturalski –
Very creative Timings Mechanism. Maybe it should becalled “Flexible Mechanism”? ? I have one important objection – setting arm can be a little bit harder for basic builders. Although it is well explained and everyone can build it. You have to perfect match every gear teeth. When you power it with motor without disabling direction lock mechanism this GBC looks and sounds perfect next to dial clock
Thorsten –
Thanks for the 42049 GBC! Great build! Also the communication and support with pv productions is just awesome! Got replies back on my questions in record time. Happy Holidays!
Carla –
A real fun build which got me started in the gbcs. Already working on one of the other bigger gbcs from the 42055 together with my husband. great moc <3