This study investigates the impact of integrating 3D-printed badges and readiness quizzes into a flipped learning engineering course to enhance student engagement in pre-class activities. The research was conducted over three academic years in a second-year Manufacturing Technology course, with the interventions progressively introduced and refined across cohorts. Data were collected on students’ performance in pre-class activities, quiz scores, technical-knowledge learning gains, and motivational responses. The results show that students exposed to the interventions demonstrated higher participation and consistent academic outcomes. Badge acquisition remained steady throughout the semester, suggesting sustained engagement. Perceptions of the flipped methodology improved, particularly when the badge incentive was increased. Motivation analysis, grounded in Self-Determination Theory, indicated that while extrinsic rewards encouraged regular participation, intrinsic motivation was more clearly associated with preparatory effort. Overall, the findings support the use of carefully aligned gamification and accountability strategies to foster engagement in flipped contexts without undermining intrinsic motivation.