After owning an i3 Mega for a while now i have noticed that the cooling is somewhat one sided. it shows up on my prints, the side closest to the fan seems fine but the printed part covers the other side.  After downloading a few replacement fan ducts and having no luck with them I decided to make my own.  This design distributes air equally to either side of the nozzle and its aslo pushes on to the original duct. youll need your printer dialed in as it requires a good fit... or glue it if you fancy, although its better to have it height adjustable.

this doesnt look much but its quick to print, fits with very little hassle and has transformed my prints.

Feed back would be good please. Thank you for downloading.

v2 is on the way to centre it around the nozzle better.