Got my prototype printed last night. My PLA had been sitting around for too long, so the end result it not what I am used to, but hey, its a prototype.
I had set the center hole for the nut to be the exact diameter of the nut, thus, I knew in advance it would not fit, but I needed to figure out by how much. Turns out, between 0.1mm to 0.2mm of gap needs to be included for a snug fit.
The other drawback is that, because of the number of blades on the fan, it cannot be milled. When I redesign the part tonight, I will probably remove 2 blades so that a 1/8 endmill can pass between the blades. That or I will ask around who can print this in resin.
At any rate, I fired up my router this morning, and I can tell you I no longer have any dust on my base plate. I will try it again with the dust shoe on, to see how it behaves. There was a lot of wind turbulence between the top of the fan and what router sends out.
At low RPM, that thing is useless. It was good at about 9,000+ RPM.
Porn shots of the fan: