e3d v6 heatsink fan duct (clip-on shroud)

This is an OpenSCAD model to generate heatsink cooling fan clip-on mounts/ducts/shrouds for the e3d v6 hotend.  It is parametric so you can create mounts for a 30mm, 40mm, 50mm, etc. fan and choose the fan's position relative to the heatsink just by modifying a couple of variables at the top of <heatsink_shroud.scad>.  You can also change mounting hole sizes in the same way.  This file builds upon the included primitive files <heatsink_clip.scad> and <heatsink_subtractive.scad> which could be useful by themselves for other purposes.  Just delete the .txt extensions to open the .scad files in OpenSCAD.  Sample .stl files for a 30mm and 40mm fan are included with M3 mounting holes.  I'm using <heatsink_shroud.scad> as a component of a larger composition to house a layer-cooling squirrel cage fan as well as an led strip to illuminate the workpiece (visible in pic).  If you'd like to add some zip tie holds, additional fans or lighting to your v6 hotend, this could be a great module to use.  If you just want to upgrade to a quieter 40mm fan, it's pretty much turn-key.  It works fine in ABS but becomes a "real" part when nylon is used.