This is the first year we had the opportunity to sponsor University of Washington’s Formula SAE team. Though they didn’t get to compete in the traditional sense, SAE still held virtual competitions for its teams. Team members Michael, Owen, and Aziz share with us their experience using the titanium and how they expected the virtual competitions to go. Looking forward to seeing where this experience gets them for next year’s competition!
PTG: Tell me a bit about your team and your role on it. What kind of experience have you gained being a part of the Formula SAE program?
Michael : I am on the manufacturing team, and my role has been to learn to use the equipment in our machine shop and utilize it to manufacture various custom metal parts for the car. We work with all of the different teams to make everything from aluminum aero bracket mounts to titanium lug studs. The manufacturing team is an excellent place to gain a lot of experience in several different areas, foremost among them being use of our 2 and 3 axis cnc mills and manual/cnc lathes. You can learn all the manufacturing theory you want, but there is simply no substitute for getting in the shop and actually making parts yourself. I also think there is tremendous value in building up the intuition for manufacturability, so that it’s something you can account for in your own future designs.
Owen: This year I worked on the control arms, the parts that connect the wheels to the body of the car. In an effort to increase rigidity and shed weight, we were working on changing the material from steel to carbon fiber, with titanium bearing housings. Firstly, this required analyzing the kinematic characteristics of the car to find the loads transmitted by each member, then running computer simulations to ensure each bearing housing could carry the required weight. Since the housings would have to be bonded into each carbon member, we also had to destructively test dozens of samples to be able to predict the bond strength. All of this was done in parallel with manufacturing a full set of the old style of steel control arms as a backup.
PTG: Why choose titanium over other materials? What advantage were you hoping to gain in competition?
Owen: Titanium is used both for its strength to weight ratio and low thermal expansion coefficient. It is principally used on rotating components, since reductions in the rotational inertia of the drivetrain are, pound for pound, around twice as effective as cutting the same amount of weight from any other part of the car. This is a rule of thumb. Our brake buttons, which attach the brake rotor to the wheel hub, utilize titanium to both insulate the hub from the high thermal loads produced from the brakes without warping, and lower the rotational inertia of the whole assembly. Wheel studs, likewise, are relatively small parts that bear the extreme loads of holding our wheels on, so titanium is a necessity. While a strong steel could potentially be used in the same role, there are three wheel studs and 6-8 brake buttons per wheel. The multiplicity of these parts drastically enhances benefits of the weight savings from titanium.
PTG: Did you machine in house? Did you run into any difficulties machining the titanium?
Michael: We do a lot of machining for the team in house. We have access to a well-appointed shop, and have amazing shop masters who are able to offer guidance, while also allowing us the freedom to try new things and learn from our own experience. As far as machining titanium goes, it really wasn’t too tricky. It took a few hours of experimenting with the feeds and speeds to make sure we were getting the best possible surface finish, but once those were dialed in, things went relatively smoothly. Machining titanium definitely highlighted for me the importance of coolant, as the few times I had problems getting coolant to the workpiece/tool interface, I was quickly rewarded with a broken insert. I will definitely do whatever I can to use the lathe with built in cooling next time. Overall, it was a really great experience getting to work with a new metal, since so many of our parts are aluminum.
PTG: Is your team planning on participating in any of the virtual competitions? What will that look like for your team?
Aziz: This year formula SAE canceled all live events and instead decided to conduct a Virtual competition. The format will be limited to three main events that we will get judged on. The first is a cost event. We will be judged on the accuracy of our costing methods of our car, and at the end I will be presenting the topic of “How to reduce the weight of the car by 10%”. The second is a design event, where the leads from the Tech teams will be presenting the top-level decisions about certain designs on the car. Finally, there will be a business presentation as the third event. The presentation is delivered to upper level executives of an imaginary organization. It ties together all factors that would influence the marketability, technical details, manufacturing feasibility and profitability of their design.
For more information on the team visit: