Makerspaces have complex access control requirements and are increasingly protected through digital access control mechanisms (e.g., keycards, transponders). However, it remains unclear how space administrators craft access control policies, how existing technical infrastructures support and fall short of access needs, and how these access control policies impact end-users in a makerspace. We bridge this gap through a mixed-methods, multi-stakeholder study. Specifically, we conducted 16 semi-structured interviews with makerspace administrators across the U.S. along with a survey of 48 makerspace end-users. We found four factors influenced administrators' construction of access control policies: balancing safety versus access; logistics; prior experience; and, the politics of funding. Moreover, administrators often made situational exceptions to their policies: e.g., during demand spikes, to maintain a good relationship with their staff, and if they trusted the user(s) requesting an exception. Conversely, users expressed frustration with the static nature of access control policies, wishing for negotiability and for social nuance to be factored into access decisions. The upshot is that existing mechanisms for access control in makerspaces are often inappropriately static and socially unaware.