Zac Waters spent his summer hunched over a 3D printer instead of a swimming pool. The 13-year-old Lehi resident logged roughly 300 hours printing, testing and assembling a custom wheelchair for a 21-month-old girl matched to him through a nonprofit's volunteer network.

The project consumed his entire break.

Waters discovered MakeGood, a New Orleans-based nonprofit that provides free 3D-printed mobility devices to children with disabilities, after watching YouTube videos about 3D printing. The organization's open-source Toddler Mobility Trainer design lets volunteer "makers" around the country build chairs at home for about $150 in materials, according to ABC4, which first reported the story Wednesday, Aug. 5.

The finished chair is tailored to its young recipient. Pink accents match the girl's favorite color. A removable cupholder and tray table snap into place. The back panel holds space for heavier medical equipment, and the footrest and headrest adjust so the chair can grow with her. Straps are printed in soft, bendable material for comfort.

"It combines my two favorite things in life: 3D printing and helping people in need," Waters told ABC4. "It just makes sense!"

His grandmother, Charlotte Waters, said the family kept him on track throughout the project. Zac compared their support to bowling ball training rails, always letting him bounce ideas until he reached the end. Charlotte Waters said she hopes her grandson remembers that making someone else's life better is the greatest legacy a person can leave. "His age does not define his ability to make a difference," she said. "His character does."

MakeGood, founded in 2021 by certified healthcare architect Noam Platt, has delivered more than 1,000 Toddler Mobility Trainers through its volunteer network. The nonprofit still has more than 550 open requests, with an average wait of about 70 days per chair. More than 2 million U.S. children need a mobility device they do not have, according to MakeGood's fundraising page.

Waters said he wants to keep developing his printing skills and hopes to one day match the expertise of the MakeGood engineering team. When he grows up, he wants to do "something techie."

Families can request a free chair at 3d-mobility.org. Residents with a 3D printer who want to volunteer as makers can sign up at makegood.design.