Here Is 3D printable Mesa Prime Hat from Warframe! This Warframe is easily one of favorite designs and high on my cosplay list. I went more simplistic with the detail than trying to do a one -for-one piece. This way it will fit better with a costume that can't mimic Warframe's unrealistic levels of detail.
Should fit most head sizes however, like with any Cosplay armor or apparel it may need to be scaled to fit your exact head.
The file contains a version broken up the way I printed and the full version.