[1] Mira Chen's first robot was a shoebox on wheels that could barely cross her kitchen floor. [2] Undeterred, she spent that winter rebuilding its drivetrain from salvaged printer motors. [3] The redesigned machine won its division at the state fair the following spring. [4] Judges praised the elegant way its software recovered from sensor errors. [5] Chen now mentors a robotics club at the same middle school where she once competed.