Nope
I guess this depends on your definition of "illegal."
If you mean machine guns, destructive devices, and other items the possession of which are highly restricted by law - - - There are a great many diagrams, drawings, and other images of the internal workings of such things widely avilable.
Some can surely be found on the internet. Many books are widely avilable. I have the Smith & Smith work, Small Arms of the World, on the shelf above my computer, and it has several such.
Johnny