Thank you so much Do3d for allowing me to gain a wonderful experience in 3D printing the helmet and making it work!. bellow you will find details of how I printed my helmet.
You'll find a link below to the youtube tutorial and review of how I printed and motorised the helmet:
Link to the hinges file:
I used the the MG996R Metal Gear High Speed Torque servo to motorise the servo also the thingiverse file is designed around this servo so it fits perfectly.
I hope this was helpful and please if you have any question do not hesitate to ask me!