This is an expansion of the helmet by big_red_frog. The .stl's are entirely his without any modification by me. His main interest was in creating the files needed to make the helmet. However he does not go into detail about other aspects of making the helmet - like wiring or magnets. This contains the files that one would use on an Ender 3 to make one adult size helmet. There is also an pdf file that discusses several aspects of building a working helmet.
The author hasn't provided the model origin yet.