I made this in an attempt to address some issues I had with the stock cooling setup on the Creality Ender-3. The 40mm axial fan that cools the hot end dumps a lot of air out the bottom of the metal box, which was causing some issues for me when printing PETG on this printer. All that airflow hitting the bed and print was lifting the first layers, much like trying to print PETG with the cooling fan on high for the first few layers. ;) I wanted a duct for that fan that snaps onto the heatsink to funnel air through it and keep it off the bed, much like the ones used on E3D style hot ends. I made that duct, then needed a way to attach the radial fan for parts cooling. I didn't like trying to hang it off the right side like stock, since the wires run down there to to the block, which means you'll need a cutout in the fan mount, leaving it somewhat weak and fragile. So I moved the fan to the left side, mounting it to the carrier plate using the two screws that held the metal box.
I wasn't able to keep it aligned so cooling ducts/nozzles intended for the stock setup would still work, so I remixed Leo's Mistral-E to fit. It prints OK, and works well, but so far I've had trouble with it melting, being so close to the nozzle. If I lower it away from the nozzle, it's a little closer to the bed than I'd like. I'm still including it because it's there. If it works well, let me know! lol The stock "scoop" should work OK, about as good as it does stock anyway. It should direct some cooling air towards the nozzle, but isn't ideal in my opinion. I may try to work up a better nozzle at some point later, unless someone else beats me to it. (Please do! lol)
I printed everything in PETG. The snap on duct for the hot end and the parts fan bracket are printed at 0.3mm layer height. The remixed Mistral-E is printed at 0.2mm layer height, and prints best with 0.4mm extrusion width, single extrusion fill. Print the hot end duct face down on the bed. Print the radial fan mounting bracket with the rear face that mounts to the carrier down on the bed, no supports needed for these two. The duct will print normally, bottom surface down on the bed, with support under the overhang. I use S3D for supports from bed only, then removed the ones inside the nozzle end, I'm not sure how to set up other slicers.
Just a quick note... I stopped working on this after trying a different solution that I found works much better. This is what I'm using now: https://www.thingiverse.com/thing:2879538 I will leave this up for anyone that want's to build off of it though.