3D-printed custom bicycle helmets
“As a mechanical engineering student at University College London, I realized that bicycle helmets had never really been innovated,” says Jamie Cook, co-founder and CEO of the bicycle helmet manufacturer HEXR. “So I came up with the idea of manufacturing helmets on a 3D printer.”
Data for 3D printing accurate to within a hair’s breadth
As no two heads are the same, why should helmets be identical? At the beginning, each cyclist’s head was scanned using iPads located in selected specialist stores to produce HEXR’s custom bicycle helmets.
Every HEXR helmet is created to fit the exact contours of the customer’s scanned head. Within seconds, the scan generates a virtual model consisting of 30,000 points. Using this data, the helmets are manufactured by 3D printing (selective laser sintering) and shipped within five weeks.
Thanks to a new iPhone app, scanning is now possible from any location. HEXR is currently 3D-printing about 2,000 custom helmets per year, and they expect to be able to manufacture as many as 50,000 in the future. Their focus is on producing huge quantities cost-effectively and high process stability.
New industrial 3D printing solution
An end-to-end solution developed by HEXR, EOS, and Siemens now aims at accelerating the new process and making it more efficient and profitable – while also maintaining the same level of quality. This will allow HEXR to expand its target group.
The heart of this workflow is the design and simulation of a high-performance industrial AM factory. To derive the optimal production system for HEXR, Siemens simulated the cost per part for different production volumes and production setups.
An end-to-end solution for customized production
In order to industrialize the product design and simulation, the CAE system Simcenter and CAD system NX as part of the Xcelerator portfolio by Siemens come into play. This software can generate a model of the helmet which allows the designers to perform crash and aerodynamic testing in the virtual environment.
Based on the scan made by using the HEXR app, a 30,000 point cloud is generated to perfectly match an individual helmet. Subsequently, this point cloud is automatically transferred in a 3D printable geometry and format.
Digital twin of the factory
Starting with a digital twin, Siemens is using its software and expertise to jointly design the optimal factory, beginning in the digital environment – and this even includes calculating the price of the product. Cloud-based monitoring solutions can help increase process stability and overall equipment efficiency (OEE), while automation solutions reduce lead time and cut manufacturing costs.
The optimal virtual factory is created with the aid of the Tecnomatix Plant Simulation factory planning and simulation software. Tecnomatix allows engineers to virtually simulate an unlimited number of different production scenarios. The digital twin of the factory gave the team the opportunity to arrive at the ideal manufacturing setup from more than 100 planning variants and to master their complex task.
Using virtual reality to tour the factory
Using virtual reality (VR), planners can “walk through” a digital model of the factory to detect and correct faults. VR is also used further down the line to provide machine operators with detailed views of the machines.
Digital platform for customer orders
Regardless of where a customer’s head is scanned, the orders need to be channeled for production. This happens via the cloud-based AM Network. Orders are uploaded directly to the platform and assigned directly to specific production locations and printers. By continuously monitoring, analyzing, and optimizing the solution, MindSphere, the open, cloud-based IoT platform, makes the entire production process transparent all the way to the end customer. With the Mendix low-code development platform, programming different apps for on-site or in-cloud deployment is very easy.
Balanced utilization of the machine fleet
To achieve a balanced machine fleet utilization, the Teamcenter product lifecycle management (PLM) system and the Opcenter manufacturing operations management (MOM) solution can be used to assign orders to specific machines.
Nesting is enabled by NX and guarantees the best possible arrangement of parts in the construction volume to utilize the given space at its best. As a result, the exchangeable frame is quickly and reliably filled, the build volume is optimally utilized, and the requisite minimum distance between parts is maintained.
NX also helps compare different design options: for example, printing the entire helmet versus printing it in different segments. This has allowed HEXR to compare how many parts can be printed in one print job, which has a high impact on the cost per part.
3D printers with selective laser sintering
The helmets are printed on EOS P 500 3D printers equipped with Simatic S7-1500 controllers. Using the additive manufacturing technology known as selective laser sintering, helmets are produced layer by layer using Polyamide-11, a plant-based material made from castor bean oil.
The process is also environmentally friendly, both because powder that’s not used for printing can be recycled and because custom 3D printing means that not a single product needs to be warehoused. In addition, HEXR uses sustainable materials for its packaging.
From scanning to industrial production
The custom 3D-printed bicycle helmet is an example of how the industrial additive manufacturing process can be seamlessly designed across the entire value chain, from head scans and virtual crash-testing to industrial helmet production. The consistent end-to-end solution will enable cost-effective, resource-saving, and customized mass production of a number of other products too, especially products that need to fit perfectly on its owner’s features.
The key outcomes of the project are convincing: The simulation based on various design and automation scenarios predicts cost per part savings of around 80 percent, of which about 15 percent are due to improved process automation. And there are more improvement strategies on the horizon.
Helmets for all kinds of sports
What’s Cook’s next move? His company doesn’t want to stop at 3D-printed bicycle helmets. HEXR also wants to manufacture custom helmets for mountain bikers, canoeists, skiers, and even race-car drivers. Because the customer’s virtual head is already stored at HEXR, more helmets can be ordered in the future without having to do another scan.
EOS is the world’s leading technology and solution provider for industrial 3D printing of metals and plastics. The independent company founded in 1989 is a pioneer and innovator of integrated solutions in additive manufacturing. The company is headquartered in Krailling near Munich, Germany.
HEXR was founded by engineers, among them Jamie Cook, who were frustrated that bike helmets hadn’t seen significant innovation in over 30 years. The helmets were researched and developed at the University of Oxford and crafted with aerodynamics partner British Cycling. The company is headquartered in London, UK.
HEXR helmets are built on a honeycomb structure that’s significantly better at controlling impact than foam. Each helmet is created to the precise contours of the rider’s head and 3D printed from data that’s accurate to within a hair’s breadth. As a result, these helmets optimally protect the most sensitive areas. At the same time, the helmet’s structure makes it so lightweight that “You can forget it’s there,” says HEXR’s Website, describing what’s claimed to be the world’s first custom bicycle helmet.
“Standard foam helmets absorb only about 30 percent of impact energy,” says Cook, “mainly because they were designed for flat surfaces, not naturally curved surfaces like our heads. That’s how we arrived at the idea of a curved, honeycomb structure manufactured on a 3D printer.” Cook and his team later developed a 3D-printed helmet that can absorb twice as much energy as a standard helmet with a foam core.