This was a fun one, and one I've wanted to make for a long time. I used probably about 50% my parts and 50% other parts I found from other meshes, mainly the helmet as I figured hey, why spend 50 hours trying to perfect my own when there is quite close to 500 darth vader helmet meshes to choose from out there on the web, and actually ended up using *MustangDaves* low poly Darth Vader helmet from here: thingiverse.com/thing:248510 which I think originated from a game mesh itself. (Thanks again mate!)
Once all the modelling was done I went over it and sculpted what was necessary - I left some internal supports in between meshes - this can be printed at 0% infill - that was the plan. This one printed out first go no issues and now sits happily on my Star Wars shelf :)
Please read the instructions for printing info and tips.
*Print shown took 5.5 hours for the main bust, 3 hours for the helmet and about an hour to paint.*
***Note on the little mouth microphone pieces.***
Mine broke off when I took the supports off the mouth and nose, but no sweat! I took 2 tiny pieces of filament, heated the ends to make little balls and super glued them to the machinery in the jaw.. and hey presto, all fixed. So the two little silver ended things are just super-glued black filament with sliver paint on the end.