Over the years we've covered our share of impressive Rube Goldberg machines, from human-powered to suitcase-sized, and created from the likes of "Brooklyn's Rube Goldberg" to alternative band OK Go.

The next one we cover might be yours—Rube Goldberg, Inc., is now accepting applications for the 2013 Rube Goldberg Machine Contest.

Open to college and secondary school students only, the theme of this year's competition is "Hammer a Nail." Entrants have to design a machine no large than six cubic feet that accomplishes this with a minimum of 20 steps from start to finish, in two minutes or less. Beyond those regulations, limitations are few: You can't use open flame, explosives, hazardous materials, or live animals.

Igus, the plastic machine parts company we looked at in an earlier post, is one of the sponsors for this year's competition. That being the case, they're willing to supply free parts—flanges, bearings, linear slides, aluminum shafting—for entrants to use in their designs. You can request Igus samples and information on available parts here.