GBC 15 Mining Plant – 42055 Building Instructions

Rated 5.00 out of 5 based on 1 customer rating
(11 customer reviews)

28.95 24.95

Note: This Great Ball Contraption (GBC) is entirely made out of LEGO parts from an Official LEGO set.

Detailed building instructions of the GBC 15 mining Plant.
Made from parts of LEGO Bucket Wheel Excavator set 42055.

– Full HD PDF building instructions
– Brief with tips & tricks
– Extra pictures
– And more

Difficulty level: Easy – Medium – Hard


Example Building Instructions

Note: This Great Ball Contraption (GBC) is entirely made out of LEGO parts from an Official LEGO set.


It has never been easier to build a complete Great Ball Contraption (GBC) loop yourself! With over 3000 parts, 400+ pages of building instructions and a footprint of 100 cm (40 inch) by 60 cm (24 inch), this GBC is the biggest, one of the most epic GBCs we have ever created. It’s way bigger than the original LEGO model and it features multiple GBC modules which all work together in harmony to make a full loop so the ball flow will never end. This GBC is entirely built using only parts from the LEGO Bucket Wheel Excavator and can be referred to as model C of the 42055. While building this GBC you will master the GBC building techniques and tricks so that you eventually also can build your own GBCs. The whole machine is powered by one LEGO motor which comes with the LEGO 42055 Set.

This GBC works great with our GBC balls.

Did you already check out the rest of our 42055 C Model family.



This GBC is a Giant factory plan for GBC balls and fits perfectly in the mining theme of the original 42055. The Dual Belt Lift Module brings the balls through a rotating tunnel to the top, a long path then lets the balls roll to a Mining Cart Module which uses a complex modified cardan gear mechanism to drive the cart in a straight line. The cart picks the balls up below and carries them to a higher level. The Moving Arm Module, powered by a slider mechanism, distributes the balls evenly over 4 weight balancing shovels who measure the amount of balls passing by. A full automatic filling mechanism loads the balls in the cups of the Rotating Cup Module which drops them again in the Dual Belt Lift Module. Minifigs workers (not included in LEGO 42055) can overview the mining from the control tower and run the whole operation on their own;) The control room can raise, lower and rotate.

While building this GBC you will learn basic engineering at it’s best like gearing, forces, sturdy constructions, automation, cool mechanism like the cardan gear mechanism, the slider mechanism and so much more!

The whole GBC is split into different parts/modules which are assembled together during the built. Because of this constructions and flexibility it is always possible to separate the modules and make your own unique configuration.
It is possible to move the whole structure at once when you hold it right. However, when moving the GBC, we advise is to place the GBC on a solid plate or to disassemble the GBC in separate modules again. Footprint GBC 15: 100 cm (40 inch) by 60 cm (24 inch).

You can separate the left and the right input of the Dual Belt Lift Module by placing a divider between the belts.
Also it is made easy to take out the yellow ball guiders so you create an in and output according to the GBC rules. In this way you can also easily connect this GBC to all our other GBCs to make the loop even bigger.

Batteries can easily be replaced.






Get the GBC Balls and accessories

The GBC Balls are available HERE.
Also take a look at our accessories.




GBC 15 Mining Plant all over the world

Did you also build one of our GBCs yourself, with your friends or family? We would love to see and share it! Send us a picture or video via one of our social media channels or get in touch via email.



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11 reviews for GBC 15 Mining Plant – 42055 Building Instructions


    Good building! Balls work great too. I admire!

  2. Michael Lam

    This Modules is very Cool . must buy !!!!

  3. Jenny

    My students absolutely loved this gbc! We got the instructions + balls last month. The build can be divided into pieces so every student can work on it’s own part. They really enjoyed this built and on the first try the machine worked beautifully. My colleagues and I were amazed by the end result. I got a video of it somewhere which I will share shortly. Definitely gonna get some more designs.

  4. Pascal

    Good clear instructions with explanation. Balls also good. Definitely recommend!

  5. Thys Brits

    Very nice design, very intricate. I found about 3 spots where I had to use different coloured pieces from what is in the instructions, nothing serious.
    Small problem I had was that I had to switch two gears around to make the “carousel” work, as the gear assembly as is in the manual makes it turn the wrong way (although it is quite possible I mixed up something else somewhere, but I made it work).

  6. jmross2013

    Awesome design however the instructions have one error which incorrectly shows a gear assembly the wrong way round (or could be my mistake) which results in the carousel trying to turn in reverse putting a lot of strain on other gears

    • Team PV-Productions

      Hi Jim,

      Thanks for your review! We checked upon the issue and fixed it in the update v5. For other issues please contact us here:

  7. mariobora05

    Actually it’s the best MOC for 42055. Thanks.

  8. Richard

    My daughter and I had so much fun building this GBC! Thanks. Hope there will be another one for the 42055 set. I will directly get it!

  9. girardflorent

    GBC 15 is a must-have if you own the 42055 BUCKET WHEEL EXCAVATOR. I built it with my 7yo son. HE LOVESIT :D Instructions are easy to follow. Actually it’s easier than the bucket wheel excavator itself, provided that you sorted the pieces when taking it appart. GBC 15 works like a charm. It required only minor tuning and now it works splendidly with no need for maintenance. It’s really fascinating to watch. Go for it !

  10. mjryland

    A nice build and looks and works better than the original BWE. Had to make a few minor tweaks but that is part of the fun.

  11. Rated 5 out of 5


    A beautiful GBC module! This module was easy to build but some steps needed more attention from me. I run this module with pv-productions balls and i make some modifications because sometimes the balls jump out the GBC. You can view all of my modifications (with a video) on my website : (the explainations are in french, sorry for non french users).
    I’am very happy about this gbc and i have already buy an other from pv-productions.

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Part List

If you don’t have the required LEGO Set there is still a chance you can build our models by using parts you already have. Most technic models use a lot of the same or replacable parts. When watching the video and checking upon the building instructions you can easily see which parts can be replaced.

What cool color design can you come up with?! Download and check the part list below.



Change Log

v1 03-03-2017: Launch

v2 15-04-2017: Step order fix

v3 04-06-2017: Mechanism improvement

v4  15-08-2017: We included the length numbers for axles, beams and other parts. A high requested feature which is really useful while building. We also added some extra information on setting up the moving arm mechanism. Make sure to get this update.

v5 02-09-2017: Corrected the color of a gray bush to red. Fixed the issue of the ring rotating in the wrong direction. Check page 235, step 28.

v6 12-11-2017: Major update! Make sure to get this one!

  • We improved the building experience by showing the steps in more logical order with extra side information when needed.
  • The building instructions are now easier to print as all pages have the same size.
  • Now the building instructions have consistent page numbering.
  • We incorporated a security feature which adds a password to the building instructions and links it to your account.
    The required password is your email address of purchase!

v7 26-11-2017: Minor changes in step order.

v8 20-12-2017: Updated watermarks & increased image size.

v9 07-02-2018: Major update! Make sure to get this one!

  • Updated shovel parts to represent the real ones. Page 42 and 150.
  • Updated and completely redesigned drive system of the Rotating Cup Module. Works now way smoother! Page 225 till 235 and 248 till 252.
  • Improved timings mechanism. Page 198.
  • Added more support for the catch tray after the Dual Belt Module. Page 12, 209 and 214.
  • Added forgotten end stop pin for the Mining Cart Module. Page 316 and 317.

v10 14-02-2018: Small part fix on page 236 step 2.

v11 24-06-2018: Update building instructions to new standard.


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