MAKE IT WORK: A TWO-WHEELER YOU CAN MAKE AT HOME
3-D-PRINTED BIKE FRAME
Fall 2016 | Story by Roger Slavens Illustrations by Clint Ford
Creating a 3-D-printed bicycle isn’t a new idea—several designers have made them before, primarily as proof of concept. But Kevin Shankwiler, ID 96, MS ID 06, a senior lecturer in the School of Industrial Design, and a team of students are working toward building a model that’s truly ready to ride.
“It’s uncharted territory to 3-D print a bike frame and then have it survive on real trails and roads,” says Shankwiler, whose students have been working on the project since the fall of 2015. “When we’re done, our ultimate goal is take the bike to the Silver Comet Trail (which runs from Atlanta to Alabama) and see how far we can ride it,” he says.
Having to bear the weight of a rider, the bumps of the trail and all the physical forces at play during a bike ride—such as tension, compression and speed—are particularly tough tests for a 3-D printed frame.
Special materials were required, and one of the project sponsors, the Eastman Innovation Lab, gave the students a high-performance, carbon-fiber-impregnated co-polyester called XT-CF 20 that fit the bill.
But the materials science and construction alone weren’t enough of a challenge for Shankwiler’s design students. They also wanted the bike frame to be able to be created by a small desktop 3-D printer that any consumer could purchase, download the design files and then build at home. Or, at least, it should use parts they could purchase online and then pick up at a local bike shop equipped to print them.
“The students also intended the frame to be customizable for different uses or have different looks,” Shankwiler says. “In their research, they found that serious riders and tinkerers like to take basic bike designs and adapt them to their own tastes.”
Printing the bike has proven a difficult task. “Using a desktop 3-D printer to produce pieces strong enough and thick enough for a bike frame turned out to be very time consuming,” he says. “Sometimes it takes as much as 12 hours to print one small component. And then when it doesn’t always print correctly—which is too often—you have to do it all over again. You have to have great patience and be willing to learn from your mistakes when you’re doing something like this the very first time.”
The students—both undergraduates and graduates—have learned along the way that the different frame parts need to be printed in a certain direction to maximize its strength and durability. “It all depends on whether the part will be a point of either tension or compression,” Shankwiler says.
Shankwiler has been teaching design classes at Tech since 2006, and for the past five years he’s focused his ID 3041 undergraduate course, “Product Development Studio I,” on designing a variety of different bikes for different purposes. Part of it is because Shankwiler is an avid cyclist. But another part is that bikes are simple machines at their core that are ripe for design adaptation.
“In that undergraduate design course, we usually don’t get past doing a rough prototype made from wood,” he says. “But in this case, the project lived on and my graduate students took it on because they wanted to see if they could make the first real-world rideable 3-D printed bike.”
They’ll find out this fall, when the bike is finally completed and the Silver Comet Trail beckons for a test run.