Would such an abrupt axial fan funnel work?
That is all the space I have so I must do a 90deg turn…
It depends on how much flow you need. Axial fans don’t develope pressure very well. Why not use a blower type fan - they develop good pressure and are compact.
I’ve tried similar and it doesn’t put out hardly any air due to back pressure. You’re better going with a turbo style fan (the real name escapes me right now) you could easily produce a turn like that
Could you add 45 degree fins to ease the transition???
yes I know about squirrel cage blowers but man those will be odd to fit…
@Griffin_Paquette I can see the back-pressure being an issue…
I don’t know anything about dimensions but … what about this? It’s an exemple http://www.pelonistechnologies.com/micro-blowers search for centrifugal fan
@Jimmy_Edwards hmmm that’s not a bad idea at all, I have actually used that very technique on another project …I completely forgot about it …
@mizar_cs they’re not readily available so getting the hands on one it’s going to be difficult…
When I was walking the floor on maker fair bay area I saw Atom 2.0 3D printer it has what looks like a heavifly modified fan even shallower than what yiu suggested. It seems they cut open one if the side.
@Step_Cia Looking for pictures online… maybe I spot something …
after 5’ search … http://www.alibaba.com/product-detail/40x40x10mm-low-noise-12v-dc-mini_60449571358.html?spm=a2700.7724857.5.1.HjzRxe&s=p
I know China is far and my orders take 30-35 days to arrive but I don’t understand why you say “not readily available” may be my english is leaking … or I missed something. Let me know
rea-di-ly 
… 35 days doesn’t mean readily if something breaks.
found someting interesting: http://forum.seemecnc.com/viewtopic.php?t=8699 … I wonder if these are actually axial fans … maybe the blades design is different so that it pushes easily air in that slim configuration…
well … I agree with you but: I didn’t dig on how much is for one but if they are enough cheap you can buy a couple as a backup. In the meantime you can try find a nearest shop … just an advice …
If you use a smaller diameter fan blade, then rotate it 90 deg. you already have a case shape for a squirrel cage fan here.
If you can’t print that you can CNC machine that part. Since you can draw it a company with Mastercam can machine from a solid works drawing.
@Florian_Ford Those are actually centrifugal fans used in laptops! You should try those… or the typical 50mm centrifugal ones all over Amazon.
3510 or 4010 blower are your keywords for google…
I think I’ve got a 4020S to fit nicely … just the screw ears are where I already have some hols on the other direction …arghhh
Found this “slim micro blower” http://catalog.pelonistechnologies.com/item/micro-blowers/all-categories-micro-blowers-rfb1804-micro-blower/rfb1804