Could you do the things you do if you had only one hand?

Each year, 1,500 babies are born in the United States without part or all of their arm, according to the Centers for Disease Control and Prevention. Many more children lose fingers or hands in accidents. Often, they overcome their limitations thanks to medical replacements. But kids quickly outgrow these devices, which cost thousands of dollars.

Now, sixth-grade science students at Alexandria Country Day School (ACDS) in Virginia are joining thousands of volunteers around the world in adding new meaning to the phrase “Let me give you a hand.” The students are using 3-D printers to create free prosthetics, or artificial limbs, for kids.

There are no motors or electronics in these robotic-looking, plastic hands. The model ACDS chose, the Raptor Reloaded, requires a bendable wrist to work. Flex the wrist downward, and the fingers and thumb can grip things such as bottles, balls, books or bicycle handles. Raise the wrist to release its grip.

The students partnered with the nonprofit group Enabling the Future (also known as e-Nable), which matches completed hands to kids in need around the world. E-Nable’s 16 designs and instructions are available free online. With access to a 3-D printer, a hand can be produced for less than $50.

Taylor Grace Peterson, 12, seemed in awe as she said, “It’s pretty cool how you can make a hand for a kid who needs one, and it doesn’t cost a lot of money.”


The prostheses are created from common materials: plastic filament, nylon cord, fishing line, Velcro and screws. Depending on the hand’s size and the speed of the 3-D printer, melting the filament to build Raptor’s 36 parts usually takes 10 to 18 hours. Rough edges are smoothed, then the pieces are hooked together. Screws and fishing line adjust the fingers’ grip – like adjusting tension on guitar strings. Nylon cord helps control the grip’s release. Velcro secures the prosthetic to the recipient’s wrist.

The class, working in teams, followed written and video instructions to assemble the prosthetics.

“Let’s try this,” “These are really cheerful looking,” “It really takes patience to get the line through these small holes” were some of the comments heard as the students practiced problem-solving.

Within 90 minutes, nine prosthetics neared completion.

“We can’t rush these,” science teacher Scott Lieberman said. “They have to work properly.”

The first recipient will be a 10-year-old boy in New Mexico who was born without a left hand. He is a huge Denver Broncos fan. So the prosthesis, built to his measurements, is orange and blue – the team’s colors.


“The beautiful part of it being so cheap to build,” Lieberman said, “is if the prototype we send next week isn’t perfect, we can adjust it and send him another one.”

Kids needing hands can even learn how to make their own prosthetics. E-Nable’s volunteers will walk them and their families through the process. As the child grows, hands can be re-sized or repaired.

These devices increase a child’s independence. But as 12-year-old Alban Erdle pointed out, there’s also a social benefit. “Having a second hand that looks cool helps them fit in better.”

Those who have experience with and access to a 3-D printer might want to try making a simple prosthetic hand. Designs and directions are free from e-Nable. Check out the Prosthetic Kids Hand Challenge at

Sixth-graders, from left, Owen Katz, Griffen Loveng, Kyan Bowman assemble prosthetic hands in class. MUST CREDIT: Photo for The Washington Post by Ann Cameron SiegalFishing string and nylon cord are used to adjust the fingers’ grip. MUST CREDIT: Photo for The Washington Post by Ann Cameron Siegal

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