This two-part print stops a ShelfTrack shelf from accidentally popping up and out of its rail. Slide the ProngBlock in and up, then slide the Wedge between the ProngBlock and the shelf. To remove, slide the Wedge sideways.

Most important setting is the 0.2mm layer height, 0.4mm nozzle so the teeth engage properly.

Supports: Not necessary.
Infill: I went with 30% gyroid.

These were designed for my shelf thickness of ¾" (19mm). The Wedge tolerates up to 5mm variance vertically, in case some shelves are mounted tighter than others.