The thing Alex Pring hated most about kindergarten wasn’t learning to cut, paste or count. It was answering the same question everyone asks when they meet the 6-year-old.

“What happened to your arm?”

Alex is missing his right arm from just above his elbow, and it’s the one thing he doesn’t like talking about.

“I mean, I’m me. So I don’t have an arm,” he said. “I still try real hard to do things like other kids using what I’ve got. But it’s getting harder the more I grow.”

Thanks to University of Central Florida engineering doctoral student Albert Manero, climbing a tree and catching a ball will get a lot easier for Alex. Manero heard about the Groveland boy’s need and pulled together a team of his friends.

In their free time they designed an arm for Alex. It was made on a 3-D printer and runs with off-the-shelf servos and batteries that are activated by the electromyography muscle energy on Alex’s bicep. Unlike adults with missing arms, children’s arms are difficult to make because of the need to miniaturize components. And most insurance companies won’t pay for them because the prosthetics need to be replaced often as the child grows.

Manero, who holds bachelor’s and master’s degrees from UCF in aerospace engineering, and his team designed and manufactured the arm for less than $350. Stratasys, one of the biggest commercial 3-D printer makers in the nation, donated some of the supplies. The team delivered the arm to Alex today.

“My mother taught us that we’re supposed to help change the world,” said Manero,  who is from the Tampa area. “We’re supposed to help make it better. That’s why we did it. The look on Alex’s face when he used it for the first time was priceless.”

The team will upload the new designs and how to build the child-size arm and hand to the Internet so anyone with access to a 3-D printer can download the blueprints and give another child with a missing arm a chance to hug with both arms.

“When he hugged me with two hands, he just didn’t let go,” said Alyson Pring, Alex’s mother. “It was amazing. I think this arm will reinforce our ‘you can do anything you set your mind to’ attitude. I think it will help his confidence, so he can see future possibilities and make them seem all the more reachable for him.”

Alex was born with part of his arm missing.  The Centers for Disease Control and Prevention estimates about 1,500 babies in the United States are born with deformed or missing arms or hands each year.

Manero, who is pursuing his Ph.D. in mechanical engineering, said he believes the team’s design could help many of these children.

Alyson Pring found Manero through the volunteer online network e-NABLE (http://enablingthefuture.org/about/). The international group of volunteer engineers, 3-D enthusiasts, occupational therapists, students, inventors and professors was started by Rochester Institute of Technology scientist Jon Schull. One of their goals is to help children without hands. Manero joined the group, in part, because he had a friend growing up that had missing fingers, and he hoped he could contribute somehow to helping others.

The organization has six hand designs available to the public online that can be printed on a 3-D printer. It didn’t have any designs for arms without a functioning elbow, however; because the hand’s motion is linked to the elbow bend

That’s where Mateo Alvarez, a UCF aerospace engineering undergraduate, came up with a key idea. Why not use the energy generated by the muscle movement in the boy’s upper arm to trigger the pull necessary in the arm chamber to open and close the hand?

Manero and the rest of the team – including friends who are majoring in electrical, mechanical and civil engineering, among other fields – spent seven weeks trying out different ideas. In early July, they had a large working prototype. The next challenge was making it small enough and light enough that a 6-year-old could move it easily.

Manero invited Alex and his family to visit the engineering college’s machine shop, where Tim Lindner, the acting manager of the shop, helped the students print the pieces needed to assemble the arm. When the team needed to take final measurements and test its prototype, Alex came back for a second fitting and he learned how to use his muscles to open and close the hand and move the arm.

“He learned pretty fast,” Manero said. “The first thing he did when he could actually control it a little bit was hug his mother. He said it was their first real hug. There wasn’t a dry eye in the room.”

There’s nothing like a firm deadline to motivate a team to finish quickly. Manero, a Fulbright Scholar, leaves for Germany on Aug. 1 to work for the German Aerospace Center. His yearlong research there will be part of his doctoral studies. But he isn’t abandoning Alex or others like him.

“We’ve already heard from another family who needs an arm,” Manero said. “We’re committed to helping who we can and I’ll be working with my team even when in Germany.

“I think 3-D printing is revolutionizing our world in many ways. I believe changing the world of prosthetics is very real. There’s no reason why this approach shouldn’t work on adults too.”

Manero also has established the Limbitless Endowed Scholarship at UCF to support future students with disabilities like Alex’s.

In addition to Manero, the following team members helped to build the arm:

Tyler Petresky: Computer Engineering (UCF sophomore), Lead Electronics Developer

John Sparkman: Mechanical Engineering (UCF master’s degree student), Electronics Developer

Mateo Alvarez: Aerospace Engineering (UCF senior), Human Integration Lead

Tim Lindner: Senior Engineer Technician/Acting Manager, College of Engineering and Computer Science Machine Shop

Kevin Tiller: Computer Science (UCF graduate), Lead Consultant

Joseph Massimo: Civil Engineering (UCF graduate), Structural Lead

Katie Manero: Photographer and Owner of KTCrabb Photography. (UCF graduate)

Tyler Pierce: Videographer, Nurse with Florida Hospital (Admitted UCF student for Fall 2014)

Nathan Puhr: Videographer, Owner of Shutterlife Productions

Chie Sparkman: Seamstress and Tailor

Jon Rowe: Electrical Engineering (UCF master’s student), Consultant and Sponsor

Stephen Sofronsky: Aerospace Engineering (UCF master’s student), CAD Specialists, Developer

Dominique Courbin: Mechanical Engineering (UCF junior), Machining Specialist and 3D Printing

Todd Harston: Mechanical Engineer (UCF senior), CAD Developer