Electric locomotive for Ikea Lillabo/Brio train (USB rechargeable) — v2.0

[Edit: I wrote an Instructable about how to build this.](https://www.instructables.com/id/Electric-Locomotive-for-Wooden-Train-Tracks-USB-Re/)

This is the second iteration of a locomotive inspired by MilanGajic's work. I wanted it to be as compact as possible (to fit in the Lillabo tunnel) while looking like a (kid's idea of a) locomotive (and in particular having a nice cow plow at the front end!).

The switch is the funnel. Turn it right once to turn the light on, twice to turn the light