2023 ASEE Annual Conference & Exposition

Additive manufacturing (3D printing) has become an integral part of engineering design and lab courses in K-12 and higher education. Low-cost and readily available 3D printers allow integration of design, prototype manufacturing, and testing which is otherwise difficult to incorporate using traditional, subtractive manufacturing methods in courses. To that end, the authors designed a four-week design-build-test (DBT) lab for junior mechanical engineering students. The lab meets the following learning goals; 1) develop proficiency in using a desktop 3D printer, 2) explain the impact of selected 3D print settings on dimensional accuracy and tensile strength of a shape, 3) evaluate the use of simulations in the engineering design process, and 4) use data to improve the design. The entire class of junior mechanical engineering students, approximately 80 students annually, are split into teams of four to five students per team. Collectively, the class investigates the impact of infill density (20, 40, 60, 80, 100 %) and three print orientations on the dimensional accuracy and strength of a printed part under tensile load. Each team uses the data in conjunction with static, structural simulations to redesign the original part without increasing the mass, volume, size, or manufacturing time. The DBT lab sequence concludes with a written report and an oral presentation. The lab provides the students with a DBT sequence while investigating a specific additive manufacturing method. The investigation allows students to apply and learn the engineering design process, the use of simulations in engineering design, experimental tensile testing, quality assurance methods, and sophisticated statistical analyses. The feedback from the students indicates that the DBT lab sequence; a) provides an appropriate level of challenge, b) keeps students engaged, c) enhances learning, and d) equips students with multiple, different tools for a successful DBT cycle, without a significant requirement for lectures.