Summer's almost over, but it's still hot. It's still muggy.
This fan prints all as a single piece, except for one small spacer that gets inserted to tighten up the assembly. Get fancy and print yours with a change of color (or two) mid-print.
(For some reason, Thingiverse is refusing to display the rendered FAN.STL. Not to worry - the file is there to download and it is correct.)
After printing, make sure all bits of the raft are removed completely. Gently separate the blades of the fan at the end. At the hub, if you squash all of the blades together, it will mostly break everything free. To completely free each blade, start with the blade on back side with the nub and rotate it out. There are internal stops on each blade to keep them from rotating too far - each blade should only pivot out by a blade's width. Repeat with each blade. Finally, press all of the blades together and then clip the little spacer over the exposed section of axle between the blades and the nub. This keeps the blades pressed together so that the internal stops operate properly.
When everything is broken free and operating smoothly, you should be able to snap the fan open and closed like in the video.