The mask, helmet, sensor cluster are based upon a pepakura unfold by MTKKTM (AKA KTM\ or KirkTrekModeler).
The pepakura unfold can be found here: http://mtkcardcraft.blogspot.com.br/2013/05/fallout-new-vegas-ncr-combat-ranger.html
The breather and helmet box pieces are my design. I added a flange to the bottom to have a flat surface to sit on the build plate that is to be removed or contoured later so your neck fits. I didn't make everything perfect and smooth, because you're a war hardened, grizzled, warrior who has seen some shit! I have not printed the final version of everything yet. I'm sure there will be changes and updates as I do.
Parts to Print:
-Mask Tube Base (optional as cover art has the breather tube on the right side, but in-game model does not, thus why I left it seperate)
-Amp (I recommend the amp made by crin here: http://www.thingiverse.com/thing:403788)
-Breather Top (made one with a screen as well as one without, If you use without and add your own screen, I provided an optional inner ring to be pressed inside the breather to hold the screen in place)
-Tail (back of mask assembly)
-Helmet Box Pieces
Find you some lenses and tint them red or green