The teams have made the trip here by car, their carefully assembled machines, months in the making, broken down and borne by trucks and U-Haul carriers. Team members lean over each other to place a golf ball here and balance a domino there, assembling their delicate contraptions for the next day's judging.

Made famous by 20th century cartoonist and erstwhile engineer Rube Goldberg, the machines that carry his name accomplish mundane tasks in over-elaborate ways — ideally with a sense of humor. Every year, Rube Goldberg Inc., the company established by Goldberg's son, hosts nationwide competitions at middle school, high school, and collegiate levels with new challenges. This year's task: erase a chalkboard.