What makes a good Rube Goldberg machine?

A successful Rube Goldberg machine – one that is competitive in Rube Goldberg machine contests – combines a number of objective and subjective qualities that fulfill tasks, follow rules and impress judges. Here is a list of the qualities that scored favorably in past years at the Argonne Rube Goldberg Machine Contest for High Schools.

• The machine works. When it starts, it runs all the way through to completion with no human intervention and completes the required task.

• It has a unifying theme. Examples of good themes include the Wizard of Oz, Star Trek, food, farm equipment, gardening, outer space, and politics. (Science themes are especially impressive to judges at Argonne's contest, since they tend to have science backgrounds, but other themes have created favorable impressions, too.) The number of possible themes is limited only by your imagination.

• No team is penalized for having electrically powered steps, but teams are encouraged to use as many steps as possible that are not powered by electric motors. Non-electrical steps are more in the spirit of Rube Goldberg's machines and tend to impress judges more. Rubber bands, magnets, inflated balloons and gravity are just a few examples of other energy sources that can drive steps in your machine.

• When using gravity to power steps, keep in mind that "top-down" machines tend not to impress judges as much as those that go both up and down. Top-down machines start with some action at the top and all the steps flow downward using gravity. Judges tend to be more impressed when some steps carry the action up toward the top.

• The students show strong team spirit. They are self-motivated, actively involved and cooperating with each other in setting up and operating the machine.

• The machine has clearly visible steps. On many machines, it's hard to follow all the steps. Judges appreciate machines that are laid out so that as many of the steps as possible are clearly visible in sequence.

• Keep the oral description of your machine simple, clear and crisp. Skits and other elaborate presentations tend to take too much time and to distract rather than entertain.

• Don't use flammable or other dangerous chemicals. This violates the rules. When the judges sit down to determine the winners, your machine will not be considered.

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