The fan points at the back of the nozzle by default/design. You can remove a screw and rotate it so it points better at the nozzle but I made this instead. Seems to work just fine. Printed Solid at 0.25mm layer height on my D5S. I had an issue with the corners lifting so stuck some mouse ears on them. There's a version with and a version without them. Might work on other printers, I just don't know. If anyone has any suggestions to improve this let me know... Update: Seemed like it was pushing air slightly the wrong place and maybe cooling the nozzle too much. I have uploaded a 'v2' which shrinks the aperture a bit. I also added a little deflector to it which may or may not help. Seems to look like it points in a better place now anyway will try some longer prints tomorrow and see what the temperatures are reading.I wanted to try and just reuse the screw that come with the original mount. They aren't going to be that strong but there's no load on them really so it should be fine. They seem to grip and tap themselves and all is holding firm. Just remove the old one and insert the new one. Simples! The original version seems like it might be cooling the hot end too much. I've tried to adjust it in v2 by closing the aperture and adding some slight deflection. I've not had the chance to test it much tonight.