This 3D printable entrance ring set provides reinforced hole plates for bird nest boxes. The set includes four precision-sized rings designed to match common cavity-nesting bird species. These plates help maintain accurate entrance sizes and protect wooden bird boxes from wear, chewing, and enlargement caused by predators or repeated use.

The rings can be installed on new nest boxes or retrofitted to existing bird houses to ensure proper species-specific access while improving durability.

Features

Precision entrance sizes for common garden bird speciesHelps prevent enlargement of nest box holesImproves durability compared with exposed wood openingsSuitable for new builds or retrofitting existing bird housesSimple mounting design for quick installationCompatible with standard FDM 3D printing

Technical Details

Entrance sizes included: 25 mm, 28 mm, 32 mm, 45 mmDesigned for FDM 3D printingMaterial compatibility: PLA, PETG, or similar outdoor-capable filaments recommendedOptimized for easy printing with minimal support requirements

Species Guide

25 mm – Blue Tit, Marsh Tit, Coal Tit28 mm – Great Tit, Tree Sparrow32 mm – House Sparrow, Nuthatch45 mm – Starling and other larger cavity-nesting birds

Files Included

4 STL files25 mm entrance ring28 mm entrance ring32 mm entrance ring45 mm entrance ring

Usage Notes

Print using weather-resistant filament if the plates will be installed outdoors.Attach using small screws or adhesive depending on nest box design.Ensure the entrance hole in the wooden bird box matches the printed ring size for proper installation.