Animators love machines, except the ones that only like airplanes. If a series has any kind of Omake, you are very likely to find whole pages devoted to detailed diagrams and blueprints of props and items used in said show. These can be as long as character biographies, and some end pages are specifically filled with this kind of information. For some series, this information is frequently All There in the Manual. Its real origin is the cutaway drawings of airplanes in popular magazines during the Second World War, which were imitated in the British comic Dan Dare as centerfolds of spaceships.