Alex Powell, 18, said her team's biggest challenge was finding a way to link one good idea with another one. Because the machines had to operate as a chain reaction, each step had to lead naturally into the next step.
“Once you got started, things just started to flow,” she said.
Powell's machine started with a teammate calling a cellphone, which vibrated, knocking over a set of dominoes. Although it took a few tries, the dominoes eventually fell, setting the machine in motion.
In that regard, Powell's team was hardly alone. Most of the teams' machines had at least one stage that caused problems during testing.
For Randy Hernandez, that step was the final stage — a crossbow that fired a nail into the center of a University of Texas Longhorns logo painted onto a foam block. The team spent quite a bit of time testing, measuring and adjusting that step, Hernandez said.
“It does work about 90 percent of the time,” he said.