Wanhao Duplicator i3 Filament Guide: 6mm and 4mm

Tried printing the other one but it literally came apart on me as if it was 2 pieces, sure enough looking at it again on Simplify3D I confirmed there was a gap between them. So I basically redrew this in Fusion 360 as 1 solid piece and while I was at it made a mirror copy so you can print for which side you want it on. You can see in my picture I also printed this other piece of my 6mm tube: http://www.thingiverse.com/thing:877258

I printed mine in PLA at 50% infill, tried at 40 and had the tube section start caving in on me (although the section where the tube goes was also smaller on my first attempt).

August 11, 2015: I've added versions for 4mm tube.