She started making robots at Wanganui Intermediate in 2007, with then teacher Andrew Szabo, and found it a fun challenge. Her first competition year was 2008.
Now at Wanganui High School, she is a member of the robotics club, which gives her access to equipment. The club had six teams in Saturday's competition.
Heidi has always competed in the theatre section, but said she liked the technical side too.
"It's inspired me to study engineering next year, at university."
Her robots - Philly (male) and Pinkallo - danced to the Beatles' song Octopus's Garden for two minutes in the competition. Their pre-programmed moves were controlled by a handheld computer.
Heidi swayed in the background, in matching'60s clothes of undersea blue and green, and got extra competition points that way.
The competition drew in schools from as far away as Rangitikei and South Taranaki.
Competitors were students in Years 6-13.
One section had robots follow a line to rescue an accident victim, another had teams of two competing in soccer, and the third was the theatre section - for dance or performance.
The competition was run by the Wanganui Intermediate robotics teacher, Leigh Harvey.
He said the school was "a bit unique" in having a full-time technology programme. He had come to it from a computer background and said it was "the best job ever".
The quality of the theatre entries especially impressed him this year.
"One of the best things about the competition was seeing the kids from all the different schools getting along. They had this common passion and were learning from each other."