Wheelchair racing is one of the most fast-paced and exciting sports in the realm of Paralympics. Yet despite significant advances in materials, technology and design, athletes today still find themselves in ill-fitting, aluminium-welded frames and hand-made gloves that can leave them injured and exhausted.
By Kira, 3ders.org April 27, 2016
Looking to inject racing chairs with the same cutting-edge technologies that have been applied to cycling, bobsledding, and other Olympic sports, BMW has turned to 3D scanning and 3D printing technology to design lightweight and aerodynamic carbon fiber wheelchairs and custom 3D printed gloves for six Team USA athletes ahead of the 2016 Paralympic Games in Rio.
Currently, racing wheelchairs are made from welded aluminium—a lightweight material, yet one that cannot handle flex. The seats are often standard-sized, meaning athletes have to bolster themselves in with padded blocks and straps. Finally, the athlete’s gloves—essential for protecting their hands as they vigorously ‘punch’ the wheels’ rims—are made from a molded plastic that fits well at first, but quickly wears down.
In an effort to give Team USA the best possible shot at gold, BMW Designworks set out to address each of these issues using 3D scanning and 3D printing technology.
The first step was to 3D scan athletes’ current chairs. The 3D imagery was run through virtual aerodynamic simulations to see how they performed and where they could be improved. A second no-brainer step was to switch from welded aluminium to carbon fiber as the primary material. Lauded for its excellent stiffness and strength-to-weight ratio, carbon fiber has already been adopted by professional cyclists, yet until now, hasn’t been used in competitive wheelchair racing.
With the 3D data and carbon fiber material in place, BMW’s designers set out to reimagine racing chairs with three key principles in mind: aerodynamics, a stiffer chassis, and completely customized seats.
The result is a minimalistic three-wheeled racing chair. If it doesn’t look like the wheelchairs you’re used to seeing, that’s the whole point. “The idea is the wheelchair disappears and it is just about the athletes,” explained Brad Cracchiola, BMW Designworks project lead.
Cracchiola went on to explain that the designers’ goal was to keep the chair as compact as possible, while optimizing energy transfer from the athlete directly into the wheels. “Anytime the chassis is flexing you are losing energy,” he said. A problem with aluminium is that once it bends, it cannot be bent back without losing strength. “A stiffer chassis keeps the wheels aligned. It is more about how you use materials. It is about finding the right balance between weight reduction, aerodynamic opportunity, chassis stiffness and durability.”
The 3D scans also allowed BMW’s designers to make each carbon fiber wheelchair customized to the athlete who will be using it. This reduces the liklihood that they will shift out of position, increasing both comfort and effective energy transfer. A similar technique was used by UK company which 3D printed customized wheelchair seats for use in the 2012 Paralympic Games.
Paralympic gold medallist and six-time world champion Josh George, who will be competing in several races this year in Rio, worked closely with BMW to help them design a racing wheelchair like no other. Although BMW has been working with the Olympic Committee for several years—they designed the innovative two-man bobsled that brought Team USA Silver and Bronze at Sochi 2014—this was their first foray into wheelchair racing.
In all, it took them a year and half to reach the finished wheelchair designs, unveiled this Wednesday, exactly 100 days ahead of the official 2016 Olympics opening date. Though the final touches are still being added, BMW has said delivery will begin in about six weeks, ensuring that they will be ready ahead of the Paralympics’ September 7 start date.
Finally, BMW also decided to re-design the wheelchair users’ gloves, which are almost as important as the wheelchair itself. Decades ago, these gloves were made from leather, which quickly wore down and led to blistering and other injuries. Eventually, clay-like, molded plastic gloves were introduced as an alternative, yet even these had the tendency to crack and wear down.
Once again, BMW used 3D scanning to capture each athlete’s individual fit, before 3D printing customized racing gloves that are significantly more durable and just a third of the weight of the plastic versions.
Ariele Rausin, a University of Illinois Student Senator and experienced wheelchair racing athlete, has helped to pioneer 3D printed wheelchair gloves using only a Makerbot 3D printer. Not only are these 3D printed versions lighter and more durable, but they are significantly cheaper as well, reportedly costing just a few dollars per pair.
Though the carbon fiber racing wheelchairs and 3D printed gloves are by no means a golden guarantee, BMW hopes they will give Team USA some added leverage. Less weight means more efficiency and energy, which could make a significant difference in those last few hundred meters.
At the end of the day, however, it’s all about the athletes themselves. “These athletes are already incredible athletes,” said Cracchiola. “What we’re looking to do is give them equipment that rises up to the level of their own talent and really optimizes the efficiency of their performance.”
Student uses 3D printing to create super cool and low cost custom racing wheelchair gloves in 3ders.org
BMW Made a Carbon Fiber Racing Wheelchair for Team USA in Popular Mechanics