Carbon fiber was on display during the 2018 Winter Olympic Games. That didn’t surprise the good folks at Utah-based Rock West Composites, given that many of their customers are manufacturers of sporting goods and equipment. To the rest of us though, the sheer volume of composite materials used during the winter games is surprising.
Take luge, for example. This death-defying form of sled racing is certainly not for the faint of heart. It is a sport in which hundredths or thousandths of a second can mean the difference. As such, teams put a lot of effort into building sleds unique to each slider in hopes that those sleds will lead to record times.
For the 2018 Winter Olympic Games, USA Luge worked with a technology company to make its sleds better through the use of 3-D printing. The sleds themselves were not printed, but the layups used to create them were. The partnership proved very beneficial to U.S. sliders. Although USA Luge only won a single medal, sliders were very competitive against dominant sliders from Germany and Austria.
Building a Composite Sled
In the old days, sleds were not highly customized. USA Luge would customize as much as they could, but their options were limited by their materials. Things are different in 2018. The combination of composite materials and 3-D printing makes it possible for engineers to build completely unique sleds for each slider, sleds that are customized to their body shapes, weight, and driving styles.
The sleds themselves have multiple components performing different functions. For example, the tower pieces that protrude from the front of the sled are used by sliders to position their legs. Position is critical to both speed and steering.
Of course, the main body of the sled is a lot better if it contours to the slider’s body. It has to be perfectly balanced over the runners if the slider expects to keep control of the sled all the way down the course. If the body of the sled is off by even the slightest amount, the slider will sacrifice speed to maintain control.
Less Weight Equals Faster Speed
At first thought it might seem as though luge teams would want heavier sleds. After all, weight should increase speed based on the laws of gravity, right? No, not in luge. This is one sport in which weight translates into drag. Sliders want sleds that are as light as possible. They want sleds that glide over the ice rather than digging into it.
Composites are ideal for this application. They offer extremely high tensile strength and rigidity while weighing less than steel and aluminum. That’s the right combination for a slider hoping to get down the track in record time.
How 3-D Printing Helped
USA Luge sleds were made using a traditional composite layup process that involved layering carbon fiber prepregs into a mold that was then cured in a large oven. The role of 3-D printing was to create the molds needed for making the layups.
Each slider was subjected to precise measurements of both body size and weight. Molds were then printed based on those measurements, and new sleds were made from the molds. The sleds were tested and, where necessary, adjustments were made. New molds were printed followed by new sled layups.
USA Luge was able to get more sleds built in a shorter amount of time with the 3-D printed molds. That made it possible for them to put together the best group of sleds they could in the weeks leading up to the games.