This study seeks to explore design tensions in introducing making activities into high school physics classrooms by examining making in semi-informal settings. Through participation in an after-school program and/or summer internship, high school students used Arduino-compatible hardware and software to develop their own scientific instruments for use in classroom physics laboratories. Here we present findings on students’ roles as co-designers and how that influenced their learning and engagement. Furthermore, we discuss issues of accessibility in designing activities in terms of physical and computational affordances. Regardless of prior experience, students were more engaged using pre-assembled robots with defined projects compared with materials and methods traditionally utilized in makerspaces. Additionally, the graphical programming language associated with these robots was more accessible than script-based languages generally used to program Arduinos. This suggests, that to provide equitable access to--and engagement with--electronic making, more material and computational scaffolding are required than what is generally provided in conventional makerspaces for implementation in high school classes.