It has never been easier to build a complete Great Ball Contraption (GBC) loop yourself! The GBC 58 Dump ‘n’ Drop features 1 module which brings GBC Balls from one side to the other. The GBC can only be used in combination with our other Great Ball Contraption and is perfect for in a GBC layout.

This GBC is entirely built using only parts from the LEGO 42167 Mack LR Electric Garbage Truck set and can be referred to as Alternate Build of the 42167. This GBC makes sure you master the GBC building techniques and tricks so that you eventually also can build your own GBCs. Learn about gearing, timings mechanisms, sturdy constructions and so much more.

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).
This GBC is established in collaboration with Noad de Lange, Petter Breedveld and Ben Jonkman who share all the same passion what we have for building great ball contraptions.

Drop it like it’s hot

Bricknerd (a LEGO news outlet) challenged us (together with Noad de Lange, Petter Breedveld and Ben Jonkman) to make a GBC from the small LEGO 42167 Mack LR Electric Garbage Truck set. Due to the very limited parts selection it was indeed a good challenge where everyone contributed ideas from their own expertise. We had a blast designing it together and in the end we accomplished the goal of making a nice functional GBC which is also very satisfying to look at. Read the story on how this GBC was created

The GBC 58 Dump ‘n’ Drop is the perfect addition next to your other GBC modules. It features an input bin, an action and an output ramp. The input bin can hold many GBC Balls. To prevent GBC Balls getting stuck there is a spinning wheel on top which makes sure the GBC Balls go left or right to the lift arms. There they wait for the lift arm to pick them up.

2 lift arms go up and down in a 180 degree phase shift of each other. Once a lift arm falls down, it triggers a timings mechanism which loads 1 GBC Ball into the bucket of the lift arm.

Note that the GBC 58 Dump ‘n’ Drop only works correctly when rotating the handle clockwise. This has to do with the fact that the cam wheel at the bottom starts pushing lift arms up at the pivot point of the lift arms. This results in a quick lift motion, which throws the GBC Balls out at the top, and a slow declining motion, which slowly loads the GBC Balls at the bottom. Perfect!

As mentioned before, the GBC Balls will be thrown out at the top, where they hit a wall to funnel the GBC Balls onto the next GBC module in line.
The gear reduction is cleverly done by using 1/2 stud bushings (4 in a row) in combination with the rubber wheels of the set. This also helps in adding friction so that the lift arms won’t fall down when you let go of the handle. Win win.

By default the GBC is powered by hand but you can motorize it. In the building instructions we have carefully explained how to do this.
You can easily connect this GBC to all our other GBCs to make the loop even bigger. More information in the building instructions.

Fun Fact

Although the LEGO 42167 Mack LR Electric Garbage Truck set uses some gears to make mechanisms work, they don’t offer any gear reduction. To make a GBC however you need most of the times some kind of gear reduction to gain power or to slow the motor down. To make it work we tinkered about various mechanisms like geneva mechanisms, steppers etc. In the end we found a great match in using a 1/2 stud bushing (4 in a row) in combination with the rubber wheels of the set. Fitting them into a 3×5 L frame made for a very firm and stable power transmission which ended up in the final design. This is truly one of those “Thinking outside the box” moments which we like so much :)

Building Instructions Preview

Preview

Upgrade your GBC 58 Dump ‘n’ Drop

Power & Automate

Get the accessories

The GBC 58 Dump ‘n’ Drop all over the world