I really like the Flashforge Adventure 3 but the fans are really loud...

So I replaced the mainboard and case fan with two ultra silence 40 mm Noctua fans, it works great but the extruder fan is also really loud.

So I designed and printed an adapter to install an other 40 mm Noctua fan.

It prints in three parts so it won't need any kind of support structure.

The printed parts fit right in the place of the old fan, so you don't need to modificative the original extruder case.

Link to the fan I used (it should probably work with other 40 mm fans too): https://noctua.at/de/nf-a4x10-flx

The original fan used 24v so you NEED TO STEP DOWN THE VOLTAGE, otherwise you will destroy the Noctua fan.

Therefore I used a small step down module, the module prevent the 500 mA the fan used:
"R-78W12-05 DC/DC-Wandler R78W, 12 V, 500 mA, SIL-3, Single" https://www.reichelt.de/dc-dc-wandler-r78w-12-v-500-ma-sil-3-single-r-78w12-05-p177271.html?r=1

You don't need to print the cover, but it looks nicer ;)

I printed all the parts with Polymer PLA, but eventually ABS works better.
--- Yes ABS works better... I printed an 7 hour long ABS project and the PLA "Fake Fan" get a bit loose due to high temperature over a long period of time.

The printer is now much more silent, the cooling is similar (if not better) in comparison to the old fan, and I`m very happy with the result.

Hope this is helpful for you, too. Have fun and happy printing!