N Scale Single Track Brick Tunnel Portal

N Scale Brick Single Track Tunnel Portal by Archimage 3D Studios This N scale single-track brick tunnel portal was designed from scratch to provide a realistic masonry tunnel entrance for model railroad layouts. The portal features detailed brickwork with a raised stone border and keystone arch blocks, inspired by classic North American railroad tunnel construction. Brick dimensions were carefully sized so the pattern prints cleanly on standard FDM printers with a 0.4 mm nozzle, making the brick texture visible and consistent without requiring a resin printer. This portal works well for: • mountain tunnels • hidden staging entrances • retaining wall transitions • scenic layout backdrops Scale Scale: N scale (1:160) Track: Single track The opening comfortably clears typical N scale locomotives and rolling stock. Print Settings Recommended settings: Layer height: 0.10 – 0.20 mm Nozzle: 0.4 mm Supports: Not required Infill: 10–15% Material: PLA Slower print speeds will help bring out the brick detail. Optional Color Change The example shown uses a manual filament color change to highlight the brickwork. Suggested color change heights: Stone Grey Color: 0 mm – 3.6 mm Brick Color: 3.7 mm – 4.1 mm Stone Grey Color 4.2 - 5mm Set the color change in your slicer if you want a two-tone effect. Painting If printing in a single color, the portal can be easily painted: Stone trim: gray or concrete tones Brick wall: red, brown, or weathered brick colors Dry brushing works well to highlight the brick texture. All brick dimensions were optimized specifically for FDM printing at N scale. License For personal use. Please do not redistribute or sell the STL files. Printed versions available A multi-color printed version of this portal will be available for purchase in my eBay store. Archimage 3D Studios More N scale scenery designs are coming soon. If you print this model for your layout, feel free to share photos — I would love to see how it turns out.