See how 3D printing has been utilized at Rochester Institute of Technology (RIT) through the use of several carbon fiber 3D printers and a metal 3D printer.
Upstate New York university RIT has roughly 19,000 students, and is the third-largest producer of undergraduate STEM degrees among all private universities in the United States. When the state of New York offered to fund an additive manufacturing print center, RIT jumped at the opportunity. The AMPrint Center houses several 3D printers, including a Markforged carbon fiber printer and Metal X system.
Students also have access to plenty of Markforged 3D printers in their classes, with the university focusing heavily on a hands-on approach to learning 3D printing. This has given RIT students a competitive advantage when they graduate, as they can use the safest and best industrial 3D printers on the market.
“The students coming out of here, be it from the 3D printing class or working in the AMPrint Center, are at a great advantage with the practical hands-on experience that they’ve gotten with the machines and the materials,” says Denis Cormier, Director of the AMPrint Center at RIT. From the campus rocket club to local and federal businesses, the AMPrint Center has increased innovation at RIT, and given students experience with real-world technical equipment.
When I am not installing Markforged printers or teaching customers SOLIDWORKS, I do long distance charity rides. These are often 50, 75, or 100 miles in 1 or 2 days. In order to ride these distances, I need to have a bike that’s both comfortable and fast. My ride of choice is a short wheel base recumbent, the Vision R40. The short wheel base fits my frame better than a road bike and gives me an added layer of comfort during the long ride. However, increased comfort means increased weight. The R40 weighs 32 points, more than twice as much as a light road bike would. One of my favorite rides of the season is the Three Notch Century. Unfortunately the weight of the chromoly frame for my Vision R40 is less than ideal for the hill climbs through the New Hampshire White Mountains. A lighter bike could make a huge difference on these long, hilly rides.
The Vision R40 recumbent bike weighs 32 pounds.
A Homemade Carbon Fiber Bike
With the strong parts that Markforged printers can create, I realized that I could create a much lighter bike affordably. A complete replacement frame and seat assembly made of 3D printed components bonded between cut sections of carbon fiber tubing is a strong, manufacturable, and affordable frame. There are just 10 unique Onyx printed components in the final assembly and 7 different sections of pre-made, bicycle frame sized, carbon fiber tubing. Some parts and tubes are used in 2 – 4 different instances within the overall assembly. The front fork, stem, and handle bars have already been purchased from eBay in carbon composite. Material costs run at about $900, which more than a $1000 cheaper than a custom built composite frame. Couple that the ability to customize the design for myself, and you have a winning formula for a carbon fiber bike.
A system CAD render of the proposed bike. The frame is comprised on stock carbon fiber tubes, connected together by Markforged connectors
The First Part
Designing a composite bike frame is one thing; proving that it’ll be lighter and strong enough is a completely different story. In order to validate my design, I printed the first element of the new frame: a left rear dropout. This part holds the rear wheel in place, so it needs to be incredibly stiff. I designed it in Solidworks and uploaded it to Eiger. I decided to use Onyx material with a few layers of High Strength High Temperature Fiberglass reinforcement. The Onyx is tough and stiff and HSHT is strong, giving the part the characteristics that needed.
The Rear Dropout, laid out in Eiger.
I printed the part on a Mark Two Enterprise kit printer. As printed, this frame component is just 26.7 grams. An equivalent metal component would be 115 grams or more. With this part, I know that the build is feasible and am pressing forward with fabrication.
“The carbon fiber strength is really, really impressive. When you have a plastic part that feels and looks like a plastic part, but it has this internal strength of something much different, it sets everybody up for a shock.”
— Sam Dicpetris, Engineer, Siemens Gas & Power