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The Rube Goldberg Challenge

BACKGROUND: A Rube Goldberg Machine is an unnecessarily complicated contraption for doing something, normally very little. Think Wallace and Grommet, or the crazy-length marble run videos you can readily watch on YouTube.

MISSION: You must build a 40x40cm module of a marble run. The module will have defined entry and exit points for a marble (not necessarily the same marble - one in, one out), and have a standard mounting system allowing it to be plugged into a standardized mounting system wall and joined to OTHER modules built by other members.

A demonstration module and framework will be provided at the Artifactory, allowing you to test your machine connections and mounting points.

TIMELINE: You have until July 3, 2010.

PRIZE: To be determined; certainly lots of Glory and Boasting Rights. A small entry fee may be prize-pooled into a voucher for a dinner for two or a nice bottle of whisky or similar.

Outside Entries Welcome: You DON'T have to be a member of the Artifactory to join the competition. You can use Artifactory facilities (normal tool hire daily rates apply), or perhaps consider becoming an associate member for a month or two?

For more information, email SKoT:


  • Module will be 40x40cm, on 16mm chipboard, MDF, similar
  • Attachment points will be 4 dowels 10mm in diameter, with centre points 50mm from each corner (measured perpendicularly from X and Y axis)
  • Marble Entry point will be centered 5cm across from left edge on top side of material (bottom of marble)
  • Marble Exit point will be centered 5cm across from left edge on bottom side of material
  • Marble will be magnetically active metal 12mm (??) marble. A demonstration Marble will be provided. Weight to be determined.
  • Marble must be delivered at a reasonably slow speed and with only vertical velocity to the next module


  • One marble in, One marble out. Not necessarily the same marble.
  • Use of stored energy in any form is ok, but devices MUST only operate when the Marble is within the module. (This is all about energy efficiency, right ? :P). Clockwork, compressed air, magnetics, electrics, etc - all on.
  • Points will be awarded according to levels of ridiculous complexity achieved, and will be detailed later
  • A machine does NOT have to be capable of repeated operation. More points will be scored for repeatability, but likewise a fiendishly over-complicated one shot device may also score highly.
  • The marble may not travel outside the X, Y confines of the module, nor more than 20cm from the backboard in the Z dimension.
  • A maximum of 1A 12V DC may be used to power your device, or a 3 bar compressed air line.
  • Modules can weigh no more than 10kg. The weight of a remote air compressor or power source will not be included in the official weight - use wires and hoses to deliver the goods.
  • The Judge's decision is Final. The Judge (SKoT) is highly open to bribes.


A rough guide:

  • 1 point for every 10cm horizontal distance the marble travels within the module
  • 5 points for every 10cm vertical distance the marble travels within the module DOWNWARDS
  • 20 points for every 10cm vertical distance the marble travels within the module UPWARDS
  • Operational repeatability without human intervention gets a 20% bonus (3 trials in a row)
  • Every use of clockwork or gears gets 20 points
  • Every use of springs gets 10 points
  • Every use of a Basic Mechanical Machine scores 5 points (lever, screw, wedge, wheel) except ramps where they are used purely as a gravity-fed path for the marble.
  • Every change in direction is worth 1 point for each 30 degrees.
  • Bonus points will be awarded for SURPRISING OCCURRENCES, ie things that one wouldn't expect from the mere motion of a marble. Sounds, flashing lights, spinning hypnodiscs, jack-in-the-boxes… depending on the level of surprise and novelty, various points will be awarded.
  • Use of an electric motor +20 points
  • Use of compressed air +30 points
  • Use of steam +50 points
  • Use of a piston +20 points
  • Use of a permanent magnet +10 points
  • Use of an electro magnet +12 points
  • Use of a pendulum, swing or other suspended orbital whatsit +15 points
  • Use of Atomic Power +100000 points

Negative Points:

  • -50 points for every kilo above 10kg
  • -20 points for failing to accept a marble from the standard testing entry module, and -20 for failing to deliver the marble to the standard testing exit module.
  • Every replacement of the marble back into the marble run after leaving the rails incurs a 20 point penalty.
  • Total scores can be negative and positive.
  • Only 3 attempts per module will be allowed on the Day Of Testing. Best score goes forward.

Module specs

Note: dimensions marked 500mm should read 400mm now.




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