Ducted cooling fan
thingiverse
If you desire Iwo's ducted cooling fan from Thingiverse (http://www.thingiverse.com/thing:5756), but only possess a 40mm fan, print his design and create an adapter ring to fit your 40mm fan. No need for glue; double-sided tape works well in securing the duct onto the build platform. For detailed instructions with photos, refer to the provided link.
Download Model from thingiverse
With this file you will be able to print Ducted cooling fan with your 3D printer. Click on the button and save the file on your computer to work, edit or customize your design. You can also find more 3D designs for printers on Ducted cooling fan.