The RailRoader was born out of a lack of truly portable motorized rail systems for moving time lapse shots. I needed something that would be fairly lightweight and fit into a bag. My ‘field test’ was a pretty demanding one: carrying this thing literally around the world. You can see some footage that was taken using the Railroader here.
The RailRoader in action in Hampi, India
The schematics I used to figure what parts I needed to make the RailRoader.