cake 3d cake structures

hi cakers,does anyone knows if there is an especific site,tutorial on how to work build up all this 3d cakes?like what tyoe of screw,pipes nor pipes?stainlesss?or not…how to bend it to whatever side?,,,iam so so so dying to learn hoe to do it, how to build it up,,,im not afraid of it,,i just need to learn the techniques of it all….pla pla pla pla pla ,,,helpppppp