At the Monroe Carell Jr. Children’s Hospital in Nashville, the newest and perhaps most revolutionary piece of mobility equipment is a 3D-printed wheelchair. Built layer by layer by a hospital gaming and technology specialist, the device represents an unexpected turning point in pediatric care. The creator, Graden Knapp, never set out to design a wheelchair, yet his grassroots project highlights a much larger, global shift currently taking place across hospitals, schools, and communities. As traditional medical supply chains continue to struggle with affordability, delivery speed, and customizability, institutions and families are increasingly taking manufacturing into their own hands, producing assistive technology that feels tailored for a child rather than a generic patient.
What is Actually Happening at Monroe Carell
The story centers on Graden Knapp, whose primary role at the hospital involves making extended pediatric stays more bearable through toys, interactive video games, and other engagement tools. While working with young patients at Monroe Carell, Knapp identified a far more fundamental gap in patient care: the facility lacked an adequate supply of wheelchairs properly scaled and suited to the unique developmental needs of its youngest patients.
Recognizing this critical shortage, Knapp taught himself a new technical skill. According to reports from regional news outlet WTVF, Knapp discovered design resources provided by "Made Good," widely recognized as the New Orleans-based disability design nonprofit MakeGood. Over the course of two to three months, he utilized these open-source blueprints to print individual components and assemble the hospital’s first nearly complete 3D-printed wheelchair. While local news reports did not explicitly specify the exact model constructed, the timeline, mission, and localized fabrication closely mirror modern open-source assistive design initiatives.
The initiative goes far beyond parking a prototype in a clinical storage closet. Knapp’s deliberate intent is for patients to take the custom wheelchairs home with them upon discharge. This transforms a clinical medical device into a personal item that a child can keep, personalize, and literally grow alongside. Although small in scale, this grassroots effort points directly toward the future of pediatric assistive technology: produced on-site, customized to the physical requirements of the individual child, and designed around the philosophy that medical equipment can be both highly functional and engaging enough for a kid to be excited to use.
The Likely Design Behind the Wheelchair: MakeGood’s Toddler Mobility Trainer
While local news coverage did not formally name the exact blueprint Knapp utilized, public disclosures from MakeGood point to a clear candidate. The organization’s flagship and widely publicized fully 3D-printable wheelchair design is the Toddler Mobility Trainer. This device matches the reported characteristics of a printed children’s mobility device sourced from a nonprofit network of collaborative designers.
Announced in late 2025 in a collaboration between MakeGood, industrial design firm LINK PBC, and nonprofit TOM Global, the Toddler Mobility Trainer is engineered for children roughly ages one to eight. Nearly every structural component—including the frame, wheels, tires, seating shell, and even supportive straps—is fabricated on consumer-grade printing hardware, specifically optimized for accessible machines like the Bambu Lab A1. The components are designed to snap together using a jigsaw-style fit without requiring complex tools, metal screws, or chemical adhesives. If a specific part experiences wear or damage, caretakers can simply reprint that individual component rather than replacing the entire mobility device.
MakeGood released the Toddler Mobility Trainer as a free, open-source file repository on MakerWorld. This ensures that anyone with access to a 3D printer and standard filament—whether a concerned parent, a school librarian, or a hospital technologist like Knapp—can manufacture a unit independently. Since its founding in 2021, MakeGood and its collaborative network have delivered thousands of free assistive devices globally, demonstrating the viability of decentralized production models in healthcare.
The Real Story: Cost
The financial implications are where this project shifts from an inspiring local news feature into a profound accessibility breakthrough. Traditional pediatric wheelchairs in the United States typically retail between $1,200 and $5,000. Furthermore, specialized pediatric or powered mobility models can easily exceed $12,000 once custom seating configurations, specialized materials, and electronic controls are factored into the total expense. These steep figures are compounded by the reality that growing children outgrow standard equipment every couple of years, compounding lifetime costs while insurance providers frequently deny or severely limit coverage claims.
By contrast, open-source alternatives like the Toddler Mobility Trainer can be manufactured for approximately $150 in raw material costs. Industry breakdowns itemize this expense as roughly eight to ten spools of PETG filament, two to three spools of flexible TPU filament, and a minimal amount of auxiliary hardware such as standard bolts, nuts, washers, and caster wheels. While local reports could not independently verify the exact build cost of Knapp’s specific institutional project, his own clinical estimates indicated that the hospital-built chair was roughly ten times cheaper than a conventional commercial model.
These dramatic cost reductions are achieved primarily by bypassing traditional manufacturing, extensive distribution networks, and heavy retail markups associated with durable medical equipment. Conventional medical devices must be engineered, tooled for mass production, manufactured in centralized factories, shipped across continents, stocked by regional suppliers, and marked up at every intermediate step. Conversely, decentralized 3D printing eliminates these layers entirely. The design exists as a digital file, and the manufacturing center becomes whatever workspace houses a printer, whether that is a hospital office, a school workshop, or a family living room.
How Accessible Is This, Really?
Evaluating the true accessibility of these devices requires looking closely at the practical requirements of decentralized manufacturing. Producing a functional mobility aid requires access to a reliable mid-sized 3D printer, a stable internet connection to download open-source files, basic technical literacy to monitor printing parameters, and a modest budget for filament and hardware supplies.
This combination of low one-time equipment expenses, inexpensive consumable materials, open-source availability, and minimal specialized medical expertise distinguishes this approach from historical iterations of do-it-yourself medical equipment. It is not merely a cheaper alternative; it represents a replicable model that schools, regional clinics, and individual families can deploy wherever basic manufacturing tools and digital access intersect.
Why This Matters Even More in the Global South
While the Nashville narrative highlights a single hospital employee utilizing one printer, the broader implications extend far beyond Tennessee. The technology holds immense potential for low- and middle-income countries, where access to essential mobility devices remains severely constrained compared to wealthy nations.
Data from the World Health Organization and UNICEF emphasize the scale of this global shortfall. Their comprehensive global reports indicate that more than 2.5 billion people worldwide require at least one assistive product, yet nearly one billion individuals are denied access. Regional analyses across developing nations show that access to necessary assistive devices can drop as low as three percent of the total population in need, compared to roughly ninety percent in high-income regions.
Additional clinical studies focusing on global wheelchair provision estimate that roughly 77 million people worldwide require a wheelchair, while only seventeen to thirty-seven percent of those individuals in less-resourced settings actually possess one. This leaves tens of millions of people without basic mobility solutions. Furthermore, WHO data notes that approximately eighty percent of individuals with disabilities reside in developing or low-resource countries—precisely the regions where commercial medical supply chains are thinnest and import tariffs make traditional equipment prohibitively expensive.
Open-source, low-cost, 3D-printed designs are uniquely positioned to address this gap. Because digital files can be downloaded instantly anywhere internet infrastructure exists, local technicians can manufacture replacement parts on demand without relying on international cargo shipments or expensive foreign currency reserves.
Why Hospitals and Institutions Should Pay Attention
The growing viability of 3D-printed assistive technology presents clear lessons for healthcare systems, educational institutions, and disability advocacy organizations. First, it demonstrates that institutional innovation often bubbles up from unexpected departments when staff members are empowered to solve everyday operational challenges. Second, it highlights the immense financial and logistical power of open-source design sharing in reducing overhead costs for essential equipment. Finally, it proves that medical devices can be engineered for personalization, dignity, and emotional resonance, shifting the perception of clinical equipment from sterile instruments of restriction into personalized tools of freedom and childhood exploration.
While 3D-printed devices are not yet positioned to fully replace clinically prescribed, highly specialized motorized wheelchairs for every complex medical case—as questions regarding long-term durability, strict weight thresholds, and formal clinical validation remain active areas of study—they have proven their immediate utility in real-world settings. For the specific application demonstrated at Monroe Carell, successfully placing a functional, well-fitted mobility device into the hands of a young child quickly and affordably is already a working reality. For other hospitals, schools, and global health organizations, the primary question moving forward is no longer whether this decentralized approach is viable, but rather when they will begin integrating on-site manufacturing into their own communities.
