This is a custom thumb screw (or wing nut) designed to replace or enhance the original hardware on the compass.

Design & GeometryShape: It features a hexagonal star-shaped grip (resembling a gear or a flower). This multi-lobed design is common in 3D printing because it provides high torque, making it easy to tighten or loosen by hand without needing a screwdriver.

Material: It is printed in White PLA filament. You can see the characteristic matte finish and slight layer lines typical of FDM (Fused Deposition Modeling) printing.

Integration: The printed plastic rod passes through the compass's metal ring to secure the pen.

Functional PurposeImproved Ergonomics: The original screw on this kind compasses is often a tiny, hard-to-turn metal nub. This larger 3D-printed head allows for a much firmer grip.

Quick Adjustment: It allows you to swap out the blue pen or adjust its height rapidly without reaching for tools.

Repair/Customization: It’s a classic example of a functional print, using a 3D printer to fix a broken part or improve a tool to make it work better for specific tasks.

Technical ObservationThe choice of a star-patterned grip is clever; it ensures that even if your fingers are a bit sweaty or slick, you can still maintain enough friction to lock the pen tightly in place so it doesn't slip while drawing a circle.