According to Business Insider, 24-year-old Guillermo Martinez from Spain has found a way to turn a hobby into a project that is helping disabled people around the globe.

Martinez told BI that he bought his first 3D printer in 2017 for less than $200, and taught himself how to use it by using YouTube tutorials. He initially used it to build robots and other things just to amuse himself.

One day, during the course of watching a tutorial on building a one-hand prosthesis, he became fascinated with printing prosthetic hands in shapes that amused him — with the hand making a thumbs-up gesture, or flipping the bird, or any number of other shapes.

However, as he was fooling around with creating these amusing prosthetic hands, Martinez became inspired to see if he could make actual working prostheses for people in need on his own computer, and was shocked by what he found.

He had already planned to take an unrelated trip to Kenya as part of an aid mission with the Bamba Project, so he contacted the people at the orphanage he was scheduled to visit to see if there might be any interest in someone trying one of his printed prosthetic hands.

According to Martinez, the next day, he had six messages from people all over Kenya asking for the hands, and he discovered that the prosthetic limbs were very needed. So he set up a company called Ayúdame3D that would pair with NGOs and other aid organizations to deliver 3D printed prostheses at low or no cost to people in impoverished countries.

The prostheses Martinez makes are surprisingly functional and easy to learn how to use, given that they are made of plastic and come off a home-use 3D printer. Using the lightweight plastic and rubber bands, the hands allow people to pick up and lift objects up to 10 kilograms in weight.

According to Business Insider, Martinez has thus far delivered over 50 working prostheses to people in countries all over the world, including Kenya, Chad, El Salvador, Morocco and Tanzania. Martinez has also started an online training program that is designed to teach kids in these countries how to generate 3D printed prostheses on their own. His goal is to set up a worldwide network of people who are able to generate and deliver low or no cost prostheses to people in need around the world.

You can read more about the company here.