Buckeye Current is Ohio State University’s student-run motorsports team. Composed of graduate, and undergraduate students this 35 member group designs, builds, and races electric motorcycles for national and international competition.
Again this year, the team is developing and racing a custom-built motorcycle for the 2016 Pikes Peak International Hill Climb “Race to the Clouds” in Colorado Springs, Colorado on June 26, 2016. This is an arduous race: 12.42-miles, 156-turns, 4720-ft climb from the middle to the top of Pikes Peak. Buckeye Current’s goal is setting a new motorcycle record.
Building a one-of-a-kind, competitive electric motorcycle requires many custom components. Critical to the motorcycle’s functionality is bussing the high-voltage battery pack. The battery pack is made of 934 cylindrical battery cells (which are not much bigger than a standard AA battery). These cells must be connected in series and parallel to form the 450V pack with bus bars that can withstand the high currents pulled from the battery pack during the race. Buckeye Current turned to EWI to manufacture over 140 bus bars for the battery pack.
Working collaboratively with Buckeye Current, EWI’s laser experts welded the sub-components for the battery pack’s nickel bus bars for the finished design. EWI used Lumentum’s 2.1kW CoreLight Fiber Laser Engine for the laser welding project. The bus bar weld jointed two nickel sheets: a 0.005-inch thick panel to a 0.020-inch thick piece. Critical for the weld’s success was it had to be round, and not penetrate through the lower 0.020-inch piece.
Round laser welds provide electrical conduction between the welded layers. (Figure 5) shows a close-up of typical round welds in the tooling.
The finished bus bars are now installed and vehicle testing is underway. EWI was thrilled to participate in this project, and wishes Buckeye Current good luck on setting a new course record later this month!