After 100 Hours of 3D Printing, a Student Built a Modular Arm for His Sister

Vitaliy Bondarchuk’s dorm-room engineering project started with a family problem: his 7-year-old sister, Bella, needed a prosthetic that could keep up with childhood, not just fit a clinic checklist. He fed designs through a 3D printer for more than 100 hours, iterating toward a modular arm that can swap attachments for different daily tasks. The work highlights a stubborn gap in pediatric prosthetics, where affordable options often sacrifice versatility and comfort. It also turned into a career calling card, helping propel Bondarchuk from Bob Jones University into GE Vernova’s leadership program.

A brother’s mission that started at home

Some tech stories begin with a pitch deck. This one began with a 7-year-old kid named Bella, and a brother who did not like the choices in front of her. At Bob Jones University, engineering student Vitaliy Bondarchuk set out to build a prosthetic arm that could actually fit a child’s life, not just a clinic’s checklist.

Pediatric prosthetics can be pricey, and they can be limiting. Bondarchuk’s goal was plain and personal: give Bella something she would want to wear, and could use for everyday moments that add up, from school projects to games at the table.

Why modular beats “one-size-fits-none”

Bondarchuk landed on a modular concept, a prosthetic designed to accept interchangeable attachments. One end could help Bella hold a paintbrush. Another could steady a set of playing cards. The point was not novelty, it was range, because kids do not live in a single activity.

That “multi-tool” approach also speaks to a bigger gap in the medical device market: families often have to choose between specialized devices or going without. In addition to day-to-day function, modularity gives a fast path to iteration, because a new idea can become a new attachment rather than a whole new arm.

100 hours of printing, and months of small fixes

The hard part was not the headline feature, it was the fit. Bondarchuk said the project required more than 100 hours of 3D printing, with repeated cycles of modeling, printing, testing, and starting over. He kept tuning the shape for comfort and control, because millimeters matter when something sits on skin all day.

One of the most important refinements was an anti-friction lining, meant to prevent irritation from rigid plastic contact. Per his account, the build took about 4 months from early work to final documentation and presentation, including technical manuals.

Daily use, an A grade, and a real job next

The payoff is wonderfully practical: Bella now uses the prosthetic daily, a quiet validation that no lab test can beat. The project also earned Bondarchuk his top academic mark, a reported A at school.

Professionally, it opened a door too. After graduating, Bondarchuk joined GE Vernova’s Operations Management Leadership Program, a track that rotates young engineers through major assignments inside a large industrial business. And with support from his older brother, also an engineer, he is still printing new attachments, with an eye toward helping more kids who have been priced out, or simply overlooked.