Abstract: University makerspaces provide students with resources to build and prototype, which is helpful in engineering design projects. In fall 2018, in a sophomore-level engineering class with a semester-long design project, we introduced a design-for-additive-manufacturing training activity with several goals in mind. We hoped to familiarize students with the interplay between design and manufacturing, reduce 3D printing failures leading to inefficient prototyping, and help novices build confidence with using 3D printing in our university makerspace. By evaluating individual homework assignments as well as team design project deliverables and grades for 58 students in the class, we seek to evaluate outcomes and participation in the prototyping process. The additive manufacturing training did not significantly decrease the occurrence of common manufacturability problems during team prototyping. However, we identified several interesting trends regarding participation. A moderate positive correlation was identified between a student’s level of initial 3D printing experience relative to their team members’ experience and the amount of prototyping responsibility that student undertook. Students who did not help prototype received lower peer review scores from their teammates than those who did. Although the participation was still unequal, the overall fraction of students who helped prototype in the semester with design-for-additive-manufacturing training was approximately 20% larger than the prior semester with no training, indicating that the training may be an effective way to foster more inclusivity in the prototyping process.