The Cheap Finger Project
I created a 3D printable finger prosthetic for those suffering from a distal phalange amputation. It uses a PIP driver to move the distal prosthesis. The prosthetic was created in OpenScad and consists of five components.
The request
Adam, a Reddit member, had lived for decades without part of his pinky after losing it in an accident. After repeated insurance denials and facing prosthetic costs reported to be as high as $20,000, he turned to a 3D-printing community on Reddit to ask whether someone might be able to help.
I responded, despite having no background in prosthetics or medicine. What attracted me was the problem itself: could an existing mechanical concept be adapted into something that was 3D-printable, durable, comfortable, and—most importantly—genuinely useful?
Iterate
Each revision was printed and shipped for real-world testing. Feedback on fit, joint travel and breakage drove the next version.
Strengthen
The original geometry was adapted for plastic printing, with vulnerable joints and pin areas reinforced to survive repeated motion.
Grip
A flexible, textured fingertip was added to improve contact with small objects while preserving the mechanical curling action.
Keep it cheap
The larger idea was simple: use accessible desktop fabrication to create affordable assistive devices.
The result: About 20 prototypes + four months
= one working finger
The finished prosthesis let Adam curl the finger again and helped with tasks including typing. The project was provided at no charge and became a practical demonstration of what patient iteration and desktop 3D printing can make possible.