Photograph by Kathy De La Torre
Robbie Paolini, 13, and Alex Liao, 12, both seventh-graders at Redwood Middle School, built a robot that shot free throws better than the average NBA player.
Science fair entry pits man against homemade machine
By Rebecca Ray
When Alex Liao and Robbie Paolini entered the annual county science fair this year, the two Redwood Middle School seventh-graders pitted man against machine.
Paolini and Liao built a robot that shot basketballs and compared its free-throw percentage to that of the average NBA player.
Paolini, 13, and Liao, 12, won one of several first-place awards for middle school students in the engineering category at the fair, the 41st Synopsys Science and Technology Championship. Thousands of middle and high school students entered the competition that took place on March 16 and 17, at the San Jose Convention Center.
In addition to receiving money from the Kozlowski family, a benefactor who has donated at least $10,000 to the fair and given $100 to each first-prize-winning project for the past two years, Paolini and Liao won a special award from the San Jose Tech Museum of Innovation. The Tech Museum gave only two awards--one for high school students and one for middle school students.
In fact, it was at the Tech Museum where Liao and Paolini got the idea for their project, Man versus Machine. When they went on a field trip to the Tech Museum with the rest of their seventh-grade class, they saw a 20-foot-long robotic arm that shot basketballs into a 15-foot-high net. Liao and Paolini, who had been brainstorming ideas about what to do for their science fair project since September, were intrigued by the robot and decided to make one of their own.
Liao and Paolini built a robot that shot balls from about 12 inches off the ground and made a half-court for it out of a square box that was about 1 foot long and 1 1/2 feet wide.
Gail Inlow, Liao's and Paolini's science teacher, said she was really impressed that they scaled down every part of the exhibit at the Tech Museum by a particular ratio--from the robot's arms to the height of the hoop to the sizes of the ball and basketball court. "That's good engineering," she said.
Because so many students at Redwood had wanted to enter the county fair, the school held its own fair to determine which projects to enter. When Liao and Paolini entered the school fair, which was held around the end of January, they had built a mechanical catapult that shot balls through a hoop. Although the project did well at the fair, Inlow questioned if it was really a robot, since it didn't have a return system.
So Liao and Paolini built a robot out of Lego Mindstorm that includes motors, axles and an RCX, a micro-sized computer that allows the user to program the motors and axles to move at certain times. Liao and Paolini connected the robot's shooting arm to a motor and axle to make it spin and shoot the ball. They also inserted netting that ran from the hoop to the robot's receiving hand so that the ball could return to the robot.
Paolini and Liao spent their winter holiday break and every weekend afterward--"hours and hours and hours," Paolini said--working on their project. Although they said they'd probably enter more science fairs, they both said they most likely wouldn't do anything as time-consuming as the robot.
A robot would shoot better than a human, they say. When they first built it, it shot at 80 percent--better than the average NBA player, who, Paolini said, shoots at around 75 percent.
But then the robot's shooting got much worse, down to around 0 percent. Although Liao and Paolini don't know why, they suspect that somebody might have accidentally bumped the robot and damaged its more sensitive parts.
Paolini's father Steve, an electrical engineer, and grandfather Robert, who used to fix computers at IBM, helped them eliminate variables that might have made the robot shoot badly.
Although the robot's shooting only improved to 25 percent, Liao and Paolini concluded it was because there was still at least one variable that hadn't been eliminated.
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