Building a pivot linkage for servo steering with 3d printed parts.
A correct length shoulder screw would work great in this application.  They have a shoulder that is held to a precise diameter and a length.  You can thread a nut on and tighten it against the shoulder to prevent clamping your pieces.  They may be hard to find locally in stores but are readily available at places like MSC, McMaster-Carr, and Bolt Depot.