Viability of 3D printing for load-bearing wheelchair components: A progressive anti-tipper prototype

Customized wheelchair components that are designed to fit the individual user and consider their preferences can greatly improve the user's quality of life, but are often cost-prohibitive using traditional manufacturing methods. 3D printing technology is advancing rapidly and has been used to manufacture assistive devices, but there is limited research on whether these methods are viable for load-bearing structural components in wheelchairs. We designed a progressive anti-tipper, an anti-tipper that provides a spring-loaded response to backwards rotation of the wheelchair. This prototype avoids the hard impact of rigid anti-tippers, and also provides increased range of motion of up to 20° rearward tip, allowing the front casters to rise far enough to climb curbs. We 3D printed our prototype using four different 3D printing methods in five materials (PLA, ASA, Resin, Onyx (Nylon+carbon fiber composite), and stainless steel). We performed function tests, ISO 7176-8 strength tests, and UTM destructive tests. The Onyx and stainless steel 3D prints passed our function and strength requirements, indicating that 3D printed parts show potential for load bearing components in wheelchairs. Further fatigue, strength, and real-world use studies are warranted to explore the viability of this technology.