It’s hard to forget Derby, the incorrigible Little-Husky-That-Could that we outfitted with 3D printed prosthetics last December. With flagless determination, Derby was all tail wags and enthusiasm over his first set of prosthetics, which we designed to help him overcome the debilitating impact of his congenitally malformed front paws. In case you missed his story, get the full impact of his amazing transformation with this video.

As many noted when Derby’s story initially came out, the first version of his prosthetics kept him fairly low to the ground. This was a very intentional choice. Derby’s first pair of prosthetics was not only a concept test for the feasibility of the overall design, it also started the process of acclimating Derby to a new elevation. We wanted to give Derby the opportunity to gradually and comfortably adjust to a vertical status quo. Had we skipped this intermediary step and immediately addressed his height in isolation of his ambulatory abilities, his story would have evolved differently. His struggles would have outweighed his successes.

Once we were confident that Derby had adapted to his initial lift, it was time for phase two of our project. Because our first circular “blade” design was so successful, our initial thought was simply to scale the original. What we had not accounted for in this second iteration, however, was that while we managed to elevate Derby to the appropriate height, the results of the scaled design were too ungainly for easy movement. Rather than walk, play and run as he had previously, Derby simply shook his paws, trying to dislodge the oversized impediments we had given him.  

Als uns klar wurde, dass es zum Bewältigen der vor uns liegenden Aufgabe nicht ausreichen würde, unser altes Erfolgsrezept nur ein wenig aufzupolieren, gingen wir wieder ans Zeichenbrett. Ein ganz neues Design musste her. Wir wollten dort, wo die Prothese Bodenkontakt hat, die gleiche adaptive Krümmung beibehalten, damit Derby sich wie zuvor drehen und herumtollen konnte. Gleichzeitig versuchten wir uns an einer Struktur, die ein Knie simulieren sollte, um eine zur neuen Höhe passende Nachgiebigkeit zu ermöglichen. Im Zuge unserer strukturellen Neubewertung mussten wir auch unsere Werkstoffauswahl überdenken. Am Ende entschieden wir uns für Nylon, da es die richtige Kombination aus Stabilität und Flexibilität bietet. Um diese Konzepte in eine echte, funktionsfähige Prothese zu übertragen, haben wir unser Design an einen unserer SLS(Selektives Lasersintern)-3 Drucker gesendet. Diese Geräte erzeugen leichtgewichtige und dabei robuste Teile (ICYMI – dies ist dieselbe Technologie, die von New Balance bei der Herstellung ihrer neuen Produktreihe von Hochleistungs-Laufschuhen mit in 3D gedruckter Mittelsohle verwendet wird). Noch am gleichen Abend hielten wir unser neues Design in den Händen und konnten es testen.

“I can’t imagine tackling this case without 3D printing,” said Tara Anderson, 3D Systems’ project lead for Derby’s prosthetics. “The key to our ability to help Derby was being able to quickly and fluidly move from design to verification to end-use part, and back to design without losing any momentum. We were able to adapt our design to suit Derby’s evolving needs in real-time.”

When we strapped Derby into this new version, we knew we had a winner. Now up to his natural height, Derby took off at a trot, testing out his new legs with his fluffy tail wagging and pink tongue lolling. Derby’s owner, Sherry Portanova, says Derby has adapted beautifully, now sitting and walking like any other dog. “This past year has been amazing for us and for Derby,” she says. “We can’t wait to see what the future holds.”

Although 3D printing has helped Derby achieve a normal dog’s stature, we know he is anything but.

Watch Derby take his new prosthetics for a spin in the video below.