Rafael Esquivel slowly raised the Raptor, watching intently as the plastic fingers folded toward the cell phone balanced on his palm.

“It’s going to work,” he whispered. “I can’t wait to take this home.”

The Raptor, a prosthetic hand produced by a group of University of Houston students using open-source designs and a 3-D printer at Cougar Bytes, gave 8-year-old Rafael a chance for something he had never experienced: two working hands.

“This is what engineers do,” Jalal Yazji, a sophomore engineering major, told Rafael and his parents. “We solve problems.”

Yazji serves as president of the UH chapter of eNABLE, which he started with fellow Cougar Daniel Bahrt, a sophomore majoring in mechanical engineering technology. The global volunteer organization provides free prosthetic hands and arms for people who need them.

Last fall, Rafael, a third-grader from Humble, became the UH chapter’s third project.

His mother, Maria Sanchez, had tried to shield him from the worst of the teasing that has come from being born without a left hand. But Sanchez is also a realist. “We say, you have to try harder,” she said. “It’s tough out there.”

Rafael discovered workarounds for a lot of things. But when other third-graders at Lakeland Elementary School began jumping rope last fall, his frustration overflowed.

“We’ll figure this out,” physical education teacher Tracy Wong promised.

That night, Wong’s 9-year-old son, Tristen, found a video about eNABLE on the internet. Wong discovered there was a chapter at UH, and she called Sanchez.

Rafael had twice been turned down for a prosthetic hand by a pediatric orthopedic hospital because he coped so well with everyday challenges, Sanchez said. She was reluctant to let her only child get his hopes up again.

UH’s eNABLE chapter did not say no.

Yazji heard about the organization while designing a prosthetic hand for a high school engineering project. Bahrt, who is vice president of the local chapter, knew computer-aided design software. Together with other friends, they thought they could take on the challenge.

“We don’t turn anyone down unless we can’t help them,” Yazji said; although most recipients are children. That’s partly because children outgrow prosthetics too quickly to make a $10,000 state-of-the-art prosthetic hand a good investment. Rafael’s hand was made with a 3-D printer at Cougar Bytes in the UH Student Center; the group has a Go Fund Me account to raise money for its own printer.

Wong and Tristen were there when Yazji, Bahrt and other members of eNABLE met in a study room at the M.D. Anderson Library one evening in November to work on Rafael’s new hand. So were Amy Wendt, his elementary school music teacher, and a dozen or more extended family members.

Sanchez and her husband, Daniel Ramirez, watched as the students began piecing the hand together. Ramirez gathered a set of extra fingers printed for the hand—a few accidents are to be expected with the hand of an active 8 year old—and tried to memorize the sequence of assembly, hoping to make any needed repairs on his own.

From the beginning after meeting Sanchez, he had been struck by how much Rafael was able to do and the effort it took to succeed. Several years ago, he insisted everyone in the family spend the day with their left hands taped shut, wanting everyone to understand the boy’s daily life.

“It was eye-opening,” Sanchez said. “It was hard. Even as his mom, I didn’t realize how hard it was.”

Still, she had seen how disappointed he was after being turned down for a prosthetic hand before. “I told him, Let’s not get our hopes up. If it happens, it happens. You’re perfect the way you are.”

But the excitement grew as the hand began to take shape. Rafael began to plan.

“First,” he said, “I’ll see if I can write my name with this hand. I’ll try stuff out.”

Sanchez and Ramirez were overwhelmed as their son grasped a cellphone in the new hand.

“Oh my god,” Ramirez gasped. “It’s working.”

Sanchez blinked back tears as she leaned over to hug Yazji and Bahrt.

“I love it,” she said.