"Thus, what was intended to be a Z scale model of a 4- by 8-foot HO scale layout became a Z scale model of a 2- by 4-foot N scale layout! After I picked myself up off the floor, I made a few quick calculations... the modeling scale would be an eye-popping 1:35,200, and the finished layout would measure .125 by .200 inches..."
The video shows the basics of the layout and the clever solution re the motor. Further details re the construction are here.
Neatorama has previously posted links to about 80 of the world's smallest things.
YouTube link. Via Nothing to do with Arbroath.