Structural mechanics is a fundamental subject in many engineering curricula. Although its disciplinary knowledge is practice-oriented, i.e., aimed at designing structures, it involves high levels of abstraction and mathematical formalism. Consequently, students often struggle to understand the physical reality behind mathematical formulas. To address this challenge in a first-year mechanical design course with 800+ students enrolled, an affordable demonstrator and a scalable hands-on learning activity were developed. The demonstrator and activity introduce students to fundamental concepts of column buckling and structural stability, guiding them in directly observing physical phenomena, interpreting their observations, and linking their discoveries to disciplinary representations. This paper presents the instructional design of the activity, its implementation in a real first-year classroom environment, and an evaluation of its effectiveness in fostering students' understanding of column buckling concepts. 110 students were present in class and participated in the activity. Students' responses to an online quiz indicate that the activity successfully helped them model their observations using disciplinary representations. Survey responses further show that students perceived the activity as increasing their understanding of the topic and appreciated the opportunity to connect theoretical concepts to real-world phenomena. The study presented in this paper serves as a pilot for a broader initiative aimed at developing similar activities for other mechanics concepts. Accordingly, the suitability of the instructional design methodology and the resulting learning activity format are discussed, offering support for engineering educators seeking to develop similar activities for their courses.
