Assembling 3D-Printed Objects Without Vision: Challenges, Strategies, and Opportunities

3D-printing can benefit blind and low-vision (BLV) users by offering tactile access to information typically conveyed visually. Complex printed models often require users to assemble multiple components, a process that relies on visual cues for sighted individuals, while the assembly experiences of BLV users remain poorly understood. In this work, we investigate how BLV users experience and navigate 3D-printed object assembly. We conducted a user study with six BLV participants under three conditions: (1) unassisted, (2) assisted by a sighted mediator, and (3) guided by step-by-step verbal instructions. Verbal instructions helped participants identify, confirm, orient, and fasten components; but challenges locating and distinguishing joints persisted. Co-designing with BLV users identified uses for tactile markers to complement verbal cues and support spatially relevant aspects of the assembly process. Our results highlight the need for assembly instructions tailored to BLV users, and we conclude with recommendations for future research and development.