Great Ball Contraption (GBC)

Fame is relative, I almost started this paragraph by saying ‘one famous example of a Rube Goldberg machine is the Lego great ball contraption (GBC)’ however I assumes it was only really famous to me and not to the world in general. As a Lego enthusiast (see dictionary definition of social pariah’ I have often watched videos of and read about the GBC and look at its artistic feature. It’s an interesting piece of engineering which I will now describe to you with all the transferred joy I can muster. A great ball contraption is a series of devices (modules) which receive Lego balls and then transfer them a distance, as a series of chain reactions. The interesting feature of GBC is that because there is a set specification a series of modules can be put together which are made by different people. The modules have to made to a set of rules so that each different module can work with any other. Each module should have an "in" basket, and will move balls to the next module's "in" basket.

The IN basket should be 10 studs by 10 studs (outside dimension) with an 8x8 opening, and should be 10 bricks (beams) tall.

The In basket should be located on the left side of the module, and output should go to the right.

Each module should be able to accept balls at an average rate of 1 ball per second. Balls can be passed continuously, or in a batch. A batch should not exceed 30 balls.

Rolling ball machines like the GBC appeal to me because they can be an elegant and intriguing repeating installation. I’ve talked a lot about the concepts and materials I want to use in my final piece and after narrowing down my options I’ve decided on doing a rolling ball device which is repeatable as my final piece, although I won’t make the work out of Lego I will take inspiration from some of the GBC module designs.

GBC Module Designs

Academies Screw

Academies screw modules are rotating helixes which slowly raise up balls. Academies screw were invented by the Grecian inventor Academies and proposed as a way of getting water above water level crops. This module type can be used to raise up balls between levels but require a motor to work.

Ferris wheel

Ferris Wheel modules are large rotating wheels with small cups around the edge, they can be used to control flow by either speeding up or slowing down and they can be used to raise balls to higher levels or lower them. This module requires a motor, preferably with speed control.

Conveyer Belt

Conveyer Belt modules work just like the convey belts at super market checkouts, they can have variable speeds and be used to raise or lower balls, they are versatile but prone to jamming, also they can’t control ball flow. This module requires a motor, preferably with speed control.

Up Pump

Up Pump modules use a com powered pusher to raise up balls, they are prone to jamming but are one of the simplest and most effective ways of raising balls. This module requires a motor and isn’t very interesting to look at but they can serve a purpose.

Train/ Mine Cart

Train/ Mine Carts are small carriages that can collect balls, transport them and deliver them. Train base modules can work on a circuit so they are repeatable and are often powered by motors within the trains. Train cart module take a lot of set up and thought but do work well as well as being visually appealing. 

Tip table

Tip Table modules are simply tray like tables where one end can be raise to create a slop so balls move using gravity to one end. Tip tables can be used to control flow and are capable to taking a lot of balls at once, they are simple and can be controlled with a simple motor and cam.

Wave Motion

Wave Motion modules are similar to Tip Table modules they work by changing levels to move balls. Wave Motion module work as a series of small slopes move up and down to create a flowing motion. The advantage of these module is they can move balls along but the module doesn’t change the height.

Bagatelle

Bagatelle Modules work similar to pinball machines, balls are fed in at the top they then roll down a slope and are filtered by small pegs. These modules are static and don’t need motors however they can be a simple way to create momentum in the ball flow, sort balls and regulate the flow speed.

Shooter

Shooter Modules simply shoot balls into targets they can be used to raise up balls and regulate flow however they are unpredictable and hard to calibrate. Visually they are the most entertaining.

Z Ramp

Z Ramps are a series of track that let balls roll downwards in a Z shaped pattern, they are static module which don’t need motors. Z Ramps only allow balls to go downward but the crate momentum and are very simple. As a side thought I could put bells at each corner to make the module more interesting.

Sweeper

Sweeper modules use a rotating arm to sweep balls along. The module is simple but requires a motor, it works at a variety of speeds so could be connected to another modules drive system, this module can move lots or only a few balls at a time and is very reliable.

Lift

A lift works like a small version of lift in a building, it can be used to move a lot of balls a long distance but is complex and require at least one motor. This king of module would be ideal as a final module because it take balls from the bottom to the top to repeat the system.

Counter

Counter Modules count the number of balls that pass through them, mechanically they are the most complex but are interesting and artistic. I’d like to have one of these modules but the mechanics may prove too difficult.