This is an add-on component for my single track tunnel portal.

The portal section can be found here https://www.cgtrader.com/3d-print-models/games-toys/other/model-railway-tunnel-portal-single-track-modular-designThis is the internal arch for a tunnel.

On many model railways people have tunnel and when a train goes through it ends up in a cavernous hole rather than something looking like a tunnel. So I have developed this add-on component for my single track portal. These come on various lengths and can be put together to create the required length. This item comes in the following lengths 12mm, 24mm, 42mm, 84mm, 168mm and 252mm

I will also be adding versions for 2nd , 3rd and 4th radius track in due course (2nd Radius 438mm, 3rd Radius 505mm and 4th Radius 572mm), for other radiuses you can use straights with curved sections together.These can also be used with tunnel portal to create bridges if required.

designed at OO gauge, 1/76.2 scale but can easily be scaled for other gauges.for HO gauge print at 87%, 1/87 Scale,for TT print at 63.5% 1/120 Scale,for O gauge UK at 175%, 1/43.5 Scale,for O gauge International print at 158%, 1/48 Scale,for N gauge print at 51.49%, 1/148 Scale

The examples in the pictures were printed on a Bambu Labs A1 FDM Printer.As normal with my designs, there is a balance between accuracy and printability, hopefully not affecting the look of the model too much.

For FDM printing, I used a 0.4mm nozzle and a layer height of 0.12mm using PLA or PLA+ filament. PETG is also a very good choice. Designed to be printed inverted with no supports.I used the following Filament: ELEGOO PLA+ Filament 1.75mm Grey 1KG - https://amzn.to/4r1qQIM (Affiliate Link)

use this link to join CGTrader and download my designs.

https://www.cgtrader.com/designers/PJD1974?referral_id=3218445