You can print almost anything, which is pretty amazing!
I know that a few years back people in the US were kicking up a fuss as someone figured out a way to 3D print all the parts needed to make a fully working gun
I also saw at a university on a site visit once that someone 3D printed a plain cube that was about 30cmx30cm and from the outside was completely natural, but inside there was a staircase printed and you could only tell once you cut it open to show it.
If you can write the code to print it, the printer can do it basically! Though you can only print in plastic, would be pretty handy to do it with metal when I need a new front wing