Five-year-old William was born without a right hand. But thanks to Chang Hsien-ling, he now has a new 3D-printed hand with movable fingers, something that his family couldn’t have afforded.

Chang lost his own right hand in a factory accident in Taiwan in September 2014. A metal engineer at a stamping plant in Tainan City, he accidentally pressed the wrong button while operating a stamping machine. The resulting injury meant his hand had to be amputated.

Chang tried several prosthetic limbs but was dissatisfied with them. The ones he could afford were not useful, while the custom-made prosthetics with movable fingers that he did want were beyond his reach.

As Chang explains in the video above, “I wasn’t very satisfied with the prosthetic hand I had bought. I was thinking very naively that since I had learned CAD and used to make moulds at my last job, that I can use all this experience to make a mechanical prosthetic hand. I was thinking very simply that I would try doing it just for fun.”

So, he acquired a 3D scanner and printer, and after watching online videos, without any medical or technical training, he printed himself an inexpensive prosthetic hand.

Since then, Chang has been making free prosthetic limbs for people who cannot afford to buy them – such as William. Said Chang, “Seeing him wear the hand and pick up things, I feel very moved. I feel like all my hard work is worth it. To be able to help disabled people, to be honest, I feel proud and also honoured.”