A GBC Collaboration

Welcome to The Great Ball Contraption Wiki, a part of the Brickimedia network!

What is a Great Ball Contraption?

A great ball contraption (GBC) is a machine which receives soccer balls or basketballs from one module and passes them to another module, rather like a bucket brigade. Modules built according to the GBC standard can be assembled into a collaborative display without pre-planning or modification. The GBC standard is minimal, permitting the builder great flexibility in designing the mechanism by which balls are moved from the input to the output. The otherwise pointless handling of balls, and the myriad ways this is accomplished, gives great ball contraptions the impression of a Rube Goldberg machine.

a stair stepper module

Upcoming GBC Events

North America

  • Makevetion, Bloomington, Indiana, US, August 29, 2015
  • BrickCon, Seattle, Washington, US, October 3–4, 2015
  • Greenfield Brick Expo, Greenfield, Indiana, US, October 10–11, 2015
  • Brickworld Fort Wayne, Indiana, US, October 24–25, 2015
  • Brickworld Lafayette, Indiana, US, November 21–22, 2015
  • Brickworld Indy, Indiana, US, March, 2016
  • Brickworld Chicago (USA), June, 2016


  • Skaerbaek Fan Weekend, Skaerbaek, DK, September 25–27, 2015.
  • LEGO World Netherlands, Utrecht, NL, October 21–27, 2015.
  • Brick 2015, London, UK, December 11–13, 2015.




www.greatballcontraption.com QR Code
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Newly updated forums



Latest reply

building instructions.

Posted by Maico on 2015-08-26 at 14:25:22.
Forum: Great Ball Contraption > Customs

1 4 On 2015-08-26 at 18:24:33
by JasonSpears

Troubleshoot modules (Step feeder & zig-zag lift)

Posted by JasonSpears on 2015-08-24 at 17:34:31.
Forum: Great Ball Contraption > Great Ball Contraption Discussion

3 32 On 2015-08-26 at 12:25:46
by JasonSpears

The vocabulary of faults

Posted by ALittleSlow (administrator) on 2015-04-03 at 05:28:47.
Forum: Great Ball Contraption > Great Ball Contraption Discussion

13 339 On 2015-08-25 at 16:58:56
by Kevinmitcham