About this 3D model

This is a train control mechanism for O scale trains. It is part of the Froggy World amusement park for adventurous frogs. To stop a train at a precise location, it must be detected and powered down, and the cross arm stops the train where I want it stopped. Video at: http://youtu.be/44i_BZaU5go Full instructions at: http://www.instructables.com/id/Froggy-World-4-The-Train/