Remember the Kupol? It was a 3D-printed bicycle helmet that we covered last month, which forwent the usual foam core. Although it didn't meet its Kickstarter goal, another 3D-printed no-foam helmet is soon to hit the market, in the form of the Hexr.
Jamie Cook first got the idea for the helmet when he was a mechanical engineering student at University College London. He then pursued the concept further as an undergrad at the University of Oxford. Now, he's CEO of a British company that's making the things.
Buyers start by going to a participating store where an app is used to do a scan of their head, resulting in a 30,000-point 3D mesh digital model. The helmet is subsequently printed according to that model – this not only ensures an exact fit, but it also minimizes waste, as helmets are only made to order.
And yes, as mentioned, the helmet doesn't utilize any foam. Cook noted that regular expanded polystyrene (EPS) foam not only hardens on impact, but it's also designed to absorb energy across a uniform, flat contact area … not a curved area, like a head. Additionally, given that it's an insulator, it's not good at conducting body heat.
With that in mind, he developed the Hexr's core system, which consists of linked hexagonal cells. Those cells soften on impact by buckling, increasing the head-to-core contact area and thus spreading the impact energy across a wide area. As a result, the helmet is claimed to be 68 percent better at controlling impact forces than regular EPS models.
Additionally, the core is printed from a material known as Polyamide 11, which is said to conduct heat eight times better than EPS. After being drawn away from the head, that heat is then vented out by air that's channelled beneath the helmet's polycarbonate outer shell. What's more, unlike petroleum-based EPS, Polyamide 11 is made from 100-percent renewable castor oil.
Plans call for the Hexr to be commercially available as of 2019, with the first year of production being limited to 500 units. Buyers can reserve a helmet now via the company website, by placing a £50 deposit on the £349 (about US$456) retail price. So far, the 3D head-size scans are only being performed in London.
