Found the helmet on thingiverse (remix link sources added) but it was non symmetrical. so I cleaned it up in tinkercad and made it a bit taller to work better as a wearable.

I scaled it to 290mm wide (max sale up for a CR-10s) and it JUST fit my massive head (actually plenty big enough just that bottom points were a tight fit)

its hollow except some selective infill where it was needed such as the top of the head where it domes over.

Printed in Sunlu PLA + Blue Print at 240c
http://amzn.to/2A5aMfz