Student Spends 100 Hours 3D Printing a Modular Arm for His Sister

A family problem turned school project

Vitaliy Bondarchuk started with a simple observation: the prosthetic options for his 7-year-old sister, Bella, were either too expensive or too limited for a kid who just wants to keep up. So the Bob Jones University engineering student decided to build one himself, using a desktop 3D printer and four months of iteration.

Modular by design

The arm is not a single static device. Bondarchuk designed it to accept interchangeable attachments, so Bella can swap out end effectors for different tasks. One attachment holds a paintbrush. Another steadies playing cards. The idea was to give her the same rough-and-tumble versatility other kids take for granted, not a fixed tool that only does one job.

The fit was the hard part

The project required more than 100 hours of printing time, plus repeated cycles of modeling, testing, and starting over. Bondarchuk said millimeters matter when something presses against skin all day. He added an anti-friction lining to prevent irritation from rigid plastic contact, and he tuned the shape for comfort and control through multiple prototypes.

From dorm room to job offer

Bella now uses the prosthetic every day. The project also earned Bondarchuk an A and caught the attention of GE Vernova, which hired him into its Operations Management Leadership Program. He and his older brother, also an engineer, are still printing new attachments and hope to help more kids who have been priced out of functional prosthetics.