Smashing pumpkins in Aurora creates a soaring lesson for Vista PEAK students

AURORA | A bright pumpkin soars across the autumn sky the day before Halloween, landing with a satisfying splotch. Around it, teams of Vista PEAK Preparatory students cheer as they measure their distance and compare designs of the machines they made to launch them.

The third annual APS Pumpkin Chunkin brings engineering and construction students together to put their skills to the test in a friendly, high-flying competition that’s as educational as it is entertaining.

“This is our third year doing this,” said engineering instructor Colin DeGroot, who co-leads the event with construction teacher Jim Prager. “This is our first year kind of blowing it up and making it this big.”

Aurora Public Schools launched this year’s event into something bigger by inviting industry partners and even the district, and it proved to be a smashing success. DeGroot and Prager said they are excited to see it grow in the future years.

The event represents a collaboration between APS’s four-year engineering education pathway and its construction program, ConstrucTECH, which is now in its third year.

About half the competitors are engineering students, from freshmen to seniors, designing and simulating trebuchets from scratch. 

Using software like Autodesk Fusion and Onshape, they model, test and refine their machines, applying physics principles such as applied force, friction reduction and projectile motion before ever cutting a piece of wood, DeGroot said.

“Our freshmen usually build simpler models,” said DeGroot. “By sophomore and senior year, they’ve learned tool usage and mechanics, so they get more creative, adding whippers and other features that require precision and testing.”

One group of engineering students, Christian Hamm, Hannah Friesen, and Alyssa Andrews, designed a trebuchet with a whipper, affectionately named Jessica, which launched farther than the other engineering group by that point.

“I just thought it was ironic,” Andrews said. “Jessica sounds like such an innocent name, but she doesn’t look very innocent.”

The team’s “whipper” design was inspired by a model from last year’s competition, but with serious upgrades.

“We took a lot of inspiration from our teacher’s design,” Hamm said. “But we added better supports and added better spacing.”

Their innovations included a control bar to prevent the counterweight from striking the throwing arm and a release bar to hold the pumpkin in place for a critical half-second before launch, ensuring smoother acceleration and preventing premature dropping. Each student took turns explaining. 

Jessica didn’t soar on the first try.

“We probably had five test launches total,” Hamm said. “At first, it just wasn’t working. The pumpkin kept hitting the weight or falling off. Once we added both bars, it finally clicked.”

Come competition time, the trio’s trebuchet launched a pumpkin 88.9 yards at 14.6 yards per second, earning them the top spot among engineering teams.

Their success came through careful math and modeling. 

“I went through a calculation, trial and error, basically plugging in different numbers into a formula and seeing which measurements would be the best, which is actually how we came up with the length of our throwing arm,” Andrews said. 

The design is not the most important part either. 

“The hardest part is developing the sling mechanism, like building the construction is easy, but getting that, like timing of the release and all that, that’s where the practice comes in,” Degroot said. 

Construction students, by contrast, start with blueprints provided by instructors, learning to follow plans, read scale drawings and execute accurate cuts, Prager said. In their second year, students focus on understanding scale and specifications of technical drawings, they practice reading tape measures, building projects according to detailed specifications and work with tolerances. 

They are tested on how closely their builds match the required specs. This project work helps the construction students develop accuracy and prepares them for more advanced work in construction, Prager said. 

“Our design elements are slightly different, just because we emphasize more of the build than we do the math iterations, the process of that kind of prefab,” Prager said. 

For the first time, local construction and engineering firms joined the Pumpkin Chunkin lineup, building their own trebuchets and mentoring students. Participants included Adolfson and Peterson Construction, JE Dunn Construction, Fransen Pittman Builders and Flintco Construction, along with Industry Builders, a local Aurora firm that has hosted students for site tours and training.

“It’s impossible to be successful without strong community and industry partners,” Prager said. 

The event allowed students to talk to local industry partners and possibly network for internships or jobs after they graduate. 

“Their involvement outside of this event is in our classroom,” Prager said. “Every one of these companies has been in our space, has been talking to kids and helping.” 

They donate time, tools, mentorship and even tech demos, Prager said. Flintco, for example, brought in an AI design program earlier this year.

Some students who have been in the program since it began three years ago have already found jobs in the field. 

Each company competed with its own “machine” design, with students and companies launching pumpkins up to 300 feet. Students used pumpkins sourced from a local farm, Trinity Acres Pumpkin Patch in Byers, selecting the ones with the ideal weight and size for optimal launch performance.

While the friendly rivalry between pathways and professionals adds excitement, the instructors said the goal goes far beyond competition.

“In engineering, we design completely from scratch,” DeGroot said. “So the students do the research, they simulate, they collect data, they develop CAD plans for their trebuchets, and then they test them and refine them for the launch.”

The event gives students a full-circle experience, DeGroot said. Students can move from design from scratch to building to launch, working through problem-solving, safety and iteration. The students also get to be competitive for multiple years, taking their mistakes this year to plan better designs next year. 

“Because engineering kind of lives in iteration, they tend to get better as they go through,” Degroot said.

On the construction side, first-year construction pathway students master basic tools and safety procedures, while advanced students refine their interpretation of technical drawings and tolerances of their “machines.”

“Some of them, it’s the very first time they’ve ever held a power tool or used a power tool,” Prager said. “And so it’s repetition. It’s rinse and repeat.” 

Both pathways are rapidly expanding, the teachers said. 

The construction pathway program now enrolls 125 students across seven classes, offering dual-enrollment college credit through the Community College of Aurora, Prager said. Graduates can either pursue an associate degree in construction management, which is transferable to CSU or CU Denver, or head directly into trade apprenticeships.

The long-term goal is to continue growing the Pumpkin Chunkin into a larger community event that showcases student innovation and industry collaboration, both teachers said. 

“It’s fun to see them be successful,” Prager said. “We have such good kids in both engineering and construction that we were expecting success. We just have such rad kids.”