Im designing a 3D printed fume extractor at the moment for the same reasons, I want more than a PC fan and some cheesy garbage filter, and I dont want to spend hundreds to get it.

My design isnt really that different, though I opted to design and print a radial fan rather than rely on scavenging one, mostly as it will inevitably fail at some point and trying to source a replacement isnt always easy. So i designed one and made two versions that will accept either a 550 or a 775 DC motor. The only piece that would keep anyone with a 3D printer from building it is the coupler that attaches the fan blade/rotor/impeller (whatever its called) to the motor. Ive had failure issues with other projects in that area and decided to machine it from aluminum. It also fits through a pair of bearings in the fan case to (hopefully) prevent any imbalance in the fan from destroying the bushings/bearings in the motor. 

I have no idea if it will work out, as its got some print time to go before I can test it. 

I do like your design, it looks well made and appears it would be very effective. Hopefully I can at least come close with mine. Or maybe I end up with a bunch of plastic scattered everywhere. Either way, I'll figure it out sooner or later!

I don't get people who say they dont mind the smell! It is awful and gives me a headache lol But aside from using a PC fan to move the fumes away, I found nothing (in a price range for a hobbyist) that would do what you plan to do.

This is an interesting project and something I'll be following :)

Thanks! The writeup is still coming so stay tuned :D I hope i can get it in the right order as hackaday io seems to put last first