e-NABLING Education • Raptor Hacking And The “Grab-Tor”



I am excited to finally get to share some of the wonderful educational activities that some of our amazing e-NABLE Volunteers have been creating for their classrooms and sharing as open-source curriculum – so that others can use these lesson plans to help get kids more excited about hacking, 3D printing and 3D design work!

Today I want to share a guest blog post from e-NABLE Volunteer Rich Lehrer, who is not only a teacher that has been dedicating his time to creating an e-NABLE based curriculum, but who is also the father of a 3D printed hand device user and someone that is passionate about inspiring the next generation of makers, to use their ideas and imaginations to create tools that can help make a difference in the lives of others.

Below, Rich shares his lesson plan and instructions as well as the open-source files needed to create “Grab-Tor” devices, which take the fingers from the “Raptor Reloaded” and hack them into fun educational tools for kids to make and get them started on 3D printing and design work before jumping head first into designing a full 3D printable hand! (And possibly to terrorize their siblings, their pets or unsuspecting school teachers…)

Not only can you make a fun hacked project, but you can earn a digital badge for your efforts when you are finished! Click the badge image below to claim yours when you have completed the Grab-Tor hack!

“Raptor Hacking” – A New Generation of 3D Printed Prosthetic Educational Activities
By Rich Lehrer

As the father of a child with an upper limb difference, one of the first educators to have his students build a 3D printed device for a child, the former Education Coordinator of the eNABLE Educators’ Exchange and the Enable Community Foundation, and a STEM and PBL teacher with more than a few teaching years under his belt, I, to put it mildly, have spent a lot of time over the past 4 years thinking about 3D printed hands and their place in educational programs.

3D printed hand building projects in K-12 classrooms have been getting a lot of attention for the past several years…and deservedly so. They provide a window into the potential that this incredible new technology holds, they provide jumping off points for conversations about STEM and human centered design, and the tantalizing prospect of students creating a device that a child with an upper limb difference might actually use provides a level of authenticity that is difficult to match.

But, speaking personally, since my students at Brookwood School in Massachusetts first started creating 3D printed hands for my son, Max, in 2013, the journey we have been on has been a delightfully challenging one. For us to get to a point where the devices that students create actually work and provide him with not just socio-emotional benefits, but also increased functionality as well, has been really hard – and has taken years, multiple iterations informed by regular feedback, the deep involvement of me as his father, and the oversight of medical professionals…and we still feel like we are just at the beginning of this work.

Because of the time, involvement of others, feedback, and constant revising that it has taken us to get to the point where our student device creators-recipient relationship is working, a few years ago I realized that other educators might be running into the same challenges. And so I began searching for simple ways to introduce students to the world of 3D printed prosthetics while allowing them to explore the STEM, critical thinking, and design principles associated with these devices and this incredible movement…without the involvement of any recipients.

This past October, I had a bit of a breakthrough. While in the middle of a 5th grade eNABLE unit with my colleague, Henry Oettinger, we were having the students work through a Design Squad Global project, building cardboard and duct tape “grabbers” to introduce some of the ideas surrounding assistive devices. Half way through the activity, we realized that if we could have the students create 3D printed grabbers based on the hands they would soon be building we would be able to provide them with increased educational experiences involving designing, critical thinking, 3D modeling, and learning of STEM concepts and skills. In an instant, we had created a new educational approach that we call “Raptor Hacking”, in which students remix the files of existing Raptor Reloaded hands to create a grabbing Raptor or “Grab-Tor”.

In the weeks that followed, we developed a highly engaging mini project in which students imported Raptor Reloaded palm files into Tinkercad and removed and grafted the “knuckles” onto a hollow cylinder that they had designed to fit over a length of PVC pipe. Once this “knuckle ring” had been printed, we also printed and attached Raptor Reloaded fingers, and then the whole device was finished off with bungees, cords, and finger rings. It also did not take us long to realize that some interesting educational potential lay in having students modify the Grab-Tors, and soon we had students importing bear claw files to graft onto the fingers in an attempt to “animalize” the devices.

I have since run several large “Grab-Tor” builds, including a day at the New York Hall of Science in which we had close to 50 families building the devices, and we seem to be at the absolute beginning of the educational applications of this project. This week I begin collaborating with Brookwood life sciences teacher, CJ Bell, on a natural selection and adaptation project in which students design removable finger extensions to change the functionality of the device in response to variations in “food” (different shapes of pasta) availability. Additionally, I hope to soon be reporting about collaborations with a number of natural history organizations in which students are able to digitally scan claws, beaks, jaws, and tentacles of different animals and graft these structures onto Grab-Tors in order to both test their functionality and actively integrate 3D printing into the study of life sciences.


If you are interested in Grab-Tor projects, please check out the 3D Printed Prosthetics page of the Impact section of my website, where you will find ready-to-print Grab-Tor files, a detailed Google Slides presentation explaining how to design, print, construct, and “animalize” Grab-Tors, and links to other innovative and educational projects centering around the use of 3D printed hand- and other Assistive Technology projects in the classroom.

Bio: Rich Lehrer is the Innovation Coordinator at Brookwood School (Manchester-By-The-Sea, MA), a teacher trainer in the fields of Project Based Learning and 3D Printing for Education for the Buck Institute for Education, TeachThought, and The Principals’ Training Center, and the former Education Coordinator for the eNABLE Educators’ Exchange and The ECF.