Mechanisms for adjusting the position of one or more print heads at an extremely fine resolution (e.g., less than 10 μm) are described herein. The adjustment mechanisms include a differential screw and an indexing wheel through which the differential screw extends. One threaded segment of the differential screw is connected to a threaded feature of a flexible body that is coupled to the print head(s), while another threaded segment of the differential screw is connected to a threaded feature of a rigid body that is coupled to a printer assembly. As the indexing wheel and differential screw rotate, the space between the flexible body and the rigid body changes based on the difference between the pitches of the threaded segments. The adjustment mechanisms described herein utilize the accurate, consistent motion of the flexible body upon experiencing pressure to effect predictable changes in the position of the print head(s).