I've been looking for one of these a long time, but was unable to find a printable model anywhere. I finally gave in and heavily modified the terminator skull found at: http://grabcad.com/library/terminator-head
and made it a single, solid mesh, learning how to use blender in the process.
Be aware, printing one of these on a self replicating printer may be a really bad idea. Hopefully the end of the world isn't open sourced ;)
The original was printed on a Fablicator. www.Fablicator.com
This is an extremely tricky model to print well. You will need support, and patience removing it (or dissolving support material)
Also, because there are a ton of low angle slopes in the model, I suggest printing it with a small layer thickness. Mine was printed at .25mm, and I feel it was far too much.
I printed this at 140% scale. The tiny actuators kept breaking on smaller ones while trying to remove the support, so going bigger is better.
This was sliced with Kisslicer in under a minute.