It has never been easier to build a complete Great Ball Contraption (GBC) loop yourself! The GBC 42 Linear Loco Lifters features 2 perfectly in sync vertical lift arms which lift the GBC Balls in a beautiful and mesmerizing way. The GBC can be used as a self contained loop or 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 Concrete Mixer Truck and can be referred to as model C of the 42112. 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).
Automation + Gearing
Pushing it to the limit!
The GBC 42 Linear Loco Lifters features 2 in sync lift arms which lift the GBC Balls in a perfectly vertical linear motion! In one cycle each lift arm will get 1 ball from a timings mechanism at the bottom. After a few seconds the sophisticated gearbox will switch direction automatically and move the lift arm up where the GBC Ball is directly released. Due to the counter weight each lift arm has on the other, a low torque is required to bring the machine alive. In the end the GBC Balls will roll down back to the input of the GBC. An in sync path divider makes sure that each lift arm has always enough GBC Balls to work with. Seeing this machine in action and understanding all the complex gearing inside really is fascinating to the eye. While building you will learn about mechanical automation, synchronization, timing mechanisms, clutches, gearing, clever lever systems and more.
Fun Fact
At first we tried to come up with creative ways to use the big concrete mixer parts. Unfortunately due to the shape of the parts their function is extremely limited. After many prototypes we had to abandon this idea for now. Perhaps in the future we will get back into this design project once again. Anyway, we thing we came up with something even better! ;)
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 42 Linear Loco Lifters
In the building instructions is explained how to easily upgrade the GBC 42 Linear Loco Lifters with various parts.
GBC Funnels
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Power & Automate
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Malcolm Jay –
Easy to build but a bit harder to get working properly. My blue gear wasn’t gripping and slipping quite right but I had a spare that solved the issue. Great entertainment for all three generations in our home once it was running.
Keelia Carver –
Mechanism works well, PDF instructions are ok.
I bought these for my five year old son who does not yet know how to read. The password protection on the PDF can be challenging since when he accidentally closed the instructions on his Ipad he needed me or my husband to retype the email to get back in.
The watermarks on the instructions cover the parts diagrams and assembly info on a couple pages.
That all said, the mechanism works well and my son had a great time putting it together.
ZTB –
I am an AFOL part of OhioLUG. Together with other members we put on shows throughout Ohio and show off our large creations with Lego – usually city themed but we’re working on expanding that!
My works range all over the place from mechs, to city, to hangable wall art, and of course GBCs!
This is not my first GBC from you guys and will not be my last!
Fun fact: I purchased the set on good faith that you’d release a GBC for it and was very excited to see the release of these instructions!
Thank you for all of your work!
Lars –
I guess I’m not the only dad who re-discovered Lego at the time his kids were old enough to build. These days, Lego Technic is much more elaborate and intricate than it used to be. So, it’s big fun for big kids as well.
As my 4 year old is a huge fan of all things involving marbles, we thought it would be nice to tear the cement wagon to pieces and give this a go.
This is the first GBC I built and i estimate it took me about 4 hrs to complete (I neatly sorted the pieces before starting). The instructions are quite straight forward, with some minor challenges with the perspective.
I found the model a bit more complicated, or at least less fool proof, than your average Lego model, so it did involve a bit more trial and error. However, it’s also that more rewarding in the end when you have a fully functioning GBC.
Looking forward to build some other models as well!