Check out the YouTube Video!

Fusion360 File Viewer - https://a360.co/49g66Fe

Instructables - https://www.instructables.com/Extremely-Tiny-Model-Train-Christmas-Ornament/

This project is a miniature model train system designed to fit entirely inside a Christmas ornament.

What began as an electronically driven track, using coils and timed control to move the train around a PCB, eventually evolved into a mechanically driven system. As the design was tested and refined, the project pivoted toward a simpler, more reliable approach that better suited the constraints of a small, self-contained build.

The final design uses a moving magnet beneath the board to guide the train along a fixed loop. As the magnet advances, the train follows, creating smooth, continuous motion with minimal wiring and fewer points of failure.

Control and timing are handled by an Adafruit ESP32 Feather V2, providing flexibility for motion control, lighting effects, and future expansion. Lighting is implemented using an Adafruit wireless LED coil mounted beneath the board, allowing small LEDs to be placed freely around the model without individual wiring. This approach keeps the system modular and easy to modify.

Mechanical components including belts, magnets, bearings, and fasteners are sourced from McMaster-Carr, while custom 3D printed parts provide structure, alignment, and enclosure. The combination of off-the-shelf hardware and printed components keeps the build accessible while maintaining precision and repeatability.

The compact, loop-based layout is intentionally constrained. The train moves steadily and predictably, contained within its ornament-sized environment. While playful in scale, the project reflects a broader focus on control, reliability, and the practical compromises that shape real engineering work.

This project is shared openly as part of the SeanVille ecosystem, where small systems run continuously and quietly in the background. Builders are encouraged to explore the files, adapt the design, and make it their own.