3D Printing Children’s Prosthetic Hands at Your Library

3D-printed prosthetic hand

3D-printed prosthetic hand

One of the most fascinating applications of a 3D printer is its ability to manufacture low-cost prosthetics. Libraries seeking to offer STEAM education, community service opportunities or a family-oriented activity should consider organizing a Hand Challenge!

Getting Started:

For the Hand Challenge at the Mastics-Moriches-Shirley Community Library, we chose the open-source “Raptor Reloaded” schematic, which is provided by the non-profit organization e-NABLE. e-NABLE is a self-described “amazing group of individuals from all over the world who are using their 3D printers to create free 3D printed hands and arms for those in need”. While the majority of each hand is rendered by your 3D printer in ABS or PLA plastic, you will also need to purchase a kit to complete the design. These kits include velcro, elastic cord, tensioner screws, foam padding and other parts which will help fasten and fine-tune the prosthetic hand. An enterprising individual can also source these items in bulk to create their own kit.

Raptor Reloaded 3D hand Kit
The Raptor Reloaded kit along with the our 3D printed parts.

Pre-printing the Schematics:

Print times will vary by model. Our fastest printer, an older 4th generation Makerbot 2X required approximately 11 hours to print all 31 pieces of the Raptor Reloaded. Our Lulzbot Taz 6 took about 19 hours. Regardless of the printer used, our event necessitated that we print our parts in advance. For our Hand Challenge, we pre-printed 15 sets of parts in a variety of colors, then mixed and matched digits, palms, wrists to create colorful designs. As the recipients of these hands would vary in size, we printed the Raptor Reloaded at 80%, 100% and 115%. We also printed a mix of right and left hands. These loose pieces were placed into Ziploc freezer bags, with care taken that they were of matching size and handedness!

raptor reloaded schematic
A Raptor Reloaded schematic.

Packaging Each Project:

Our next step in the Hand Challenge was to create project bins that would contain all the tools and materials the working groups of participants would need. Aside from the 31 pieces of the Raptor Reloaded and the kits from 3DUniverse, we also added the following:

Hand Challenge Kit

  • a printed how-to guide from Instructables
  • needle nose pliers
  • crazy Glue
  • fine sandpaper
  • Philips-head screwdriver

Promoting the Event:

While we gave the Hand Challenge prominent placement in our print newsletter, it can be difficult to communicate a new or unfamiliar technology to people. As such, we wanted to engage in a more interactive, experiential marketing campaign. Basically, we wanted to show by doing. We achieved this by setting up an ongoing display on the library’s main floor with a 3D printer rendering the prosthetic hands. Literature describing this process and 3D printing more generally was placed in acrylic holders. Finally, a poster describing the event and how to participate was placed next to the printer. During peak hours, a staff member was assigned to the printer to answer patrons’ questions on the technology, market our other 3D printing programs/services, and, of course, promote the Hand Challenge itself.


Running the Event:

For our Hand Challenge, registration was open to fifty people, ages 12 and up. Registrants would work in small groups to assemble a total of fifteen hands. We estimated the build time at approximately 4 hours, which we split over consecutive Wednesday afternoons. To oversee the event, five staff members were given a half-hour orientation on the assembly process, which would largely be patron driven. In addition to the print instructions, laptops were provided at each table with a video walkthrough on the assembly process. We also utilized an augmented reality app for Android devices. Essentially staff stood ready to troubleshoot, source replacement parts and otherwise facilitate the workshop.

Patron using a YouTube tutorial to assemble the Raptor Reloaded prosthetic.
Patron using a YouTube tutorial to assemble the Raptor Reloaded prosthetic.

While we had pre-printed each set of parts, we also ran one of our 3D printers throughout the workshop. This allowed participants to witness the process, and built in some room for error. If a piece was broken or went missing, we were able to quickly replace it by stockpiling excess pieces. In our experience, the wrist piece was most at risk of breaking, while the smaller pins tended to go missing. The majority of the first session involved initial assembly of the hand, while session two mainly consisted of threading the cord throughout the hand and appropriately tightening the tensioner screws. Between sessions, a note with the names of each “team” was placed in the bins containing the in-progress hands so everyone could easily retrieve their project.

In-progress prosthetic hand
An in-progress prosthetic hand.


Despite some concerns over losing patrons between sessions, nearly all returned! Additionally we had some individuals show up that had missed the first session. These newcomers took up unfinished projects. We were also able to create two extra kits out of the excess parts we had been printing throughout the first workshop for one new group that wished to start fresh. In total, fifteen Raptor Reloaded Prosthetics were completed. These completed hands were given a thorough inspection by staff, who devoted a few hours to trimming excess cordage and fine tuning the tension in the fingers. Once these prosthetics pass inspection, they will be boxed and shipped to the South Carolina-based non-profit Prosthetic Kids Hand Challenge to be matched with children in need.

a set of prosthetic hands
A set of nearly-complete Raptor Reloaded prosthetic hands.

The library received some nice media coverage for the Hand Challenge, with several articles appearing in local and regional papers. More importantly, our community worked together to improve the lives of others. We’ve been bombarded with patron (and staff) requests to hold another Hand Challenge. At this time we are considering organizing two events a year, with one being a 4-hour marathon session. Plans are in the works to make the kits available in our Teen Services Department for patrons needing community service hours for their Participation in Government requirement, a practice we’ve seen at other area libraries.

2 thoughts on “3D Printing Children’s Prosthetic Hands at Your Library

  1. Could you tell me if they are a library in my area that could help me make 3d printed hand for my grandaughter my zip code is 84067. I’am 74 disabled but I like to fix things so if you have the parts for the hands send me the parts I will put them together for you and send them back hope I can help thanks

    1. Henry,

      Thanks for reaching out! Based on your zip, it looks like your local library may be the Southwest Branch in Weber County. I’d reach out to them and see if they have a 3D printer available. Their contact info is here: https://www.weberpl.lib.ut.us/visit/visit-southwest-branch

      Separately, the non-profit e-NABLE has resources for those seeking a prosthetic hand. That info can be found here: http://enablingthefuture.org/ineedahand/

      Take care!

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