most of this is a working progress, just fitted this no idea if its any better, (much quieter!!!)
used with Irondmax's 40mm fan grill in pic
http://www.thingiverse.com/thing:638353
fits with a 40mm fan (pretty tight fit)
flip it 180 degrees so it prints the correct way up, no need for support then
TOP_FAN_MOUNT.stl | 4.4MB |