(Final Update)Ender 3 v3 KE silent idle fan mod

Final update 2024-11-01: I will leave all my previous posts because there might be some useful info to someone (product links etc…). To control one fan is nice, but then the other fan ruins everything. So my advice is either do it for both fans or don't do it at all :) I wasn't planning this upgrade, but after some bad advice from the internet I had to make it right. You can check the progress from the beginning.

!!!TEST Voltages before assembly. Double check all polarities as well. Most connections needs soldering. Printers PSU has a potentiometer as well, so DO NOT TOUCH IT, unless you know what you're doing!!!

Main thing is that to power both fans, don't use fan headers. Take 24V straight from the psu. I didn't have the proper connectors and longer wires, so I did everything the old school way, but everything came out great.

I took two pcs of a slightly thicker wire, connected to psu V+ and V-, other ends of wires goes to buck converters IN socket. Then take ends of wires of both fans. Twist together usually red (+) with red (+), black (-) with black (-). Insert twisted parts to buck converters OUT socket (with red led), tighten everything. I used hot glue so the wires would not come out. And that's basically it. Now the printer has two empty fan headers that can be used and is silent or whisper quite when IDLE. I made a basic case to hold XL4016 buck converter and a custom knob: 
https://www.printables.com/model/1057890-xl4016-case
https://www.printables.com/model/1062225-xl4016-custom-potentiometer-knob

Update: 2024-09-18 - Changed the PSU fan to Sunon Maglev 6015 24V 4300rpm https://www.aliexpress.com/item/32832502877.html?spm=a2g0o.order_detail.order_detail_item.3.7773f19cCr4B1O . Needed to solder the connector from previous fan on to a new one. There are 4 screws on the top of the printer that you need to unscrew to make PSU loose. Then unscrew 4 screws on the psu, 2 left side 2 right side, pull up the cover slightly, disconnect the fan. Replace the connector and assemble everything as it was. 
   Added a buck converter with potentiometer (XL4016- https://www.aliexpress.com/item/32910553379.html?spm=a2g0o.order_list.order_list_main.101.1b171802RWcfGA ) for the motherboard fan. Installation is pretty much straightforward. Cut off the connector from the fan and connect to the “IN” socket (the one without red LED) You will need to connect this wire to the motherboard fan header. Then connect the fan to “OUT” socket (with red LED). I added hot glue so the connection will stay firm. Drill 8mm hole on the side for the knob and place buck converter inside the printer with all wires connected properly. I fixed it in place with hot glue. Maybe i will make an enclosure for it some day. With this new potentiometer I can control the fan in ~10dBA range or turn it off completely. I know that XL4016 is overkill, but I couldn't find smaller one with potentiometer and i might be able to control two fans(mobo and psu) with one knob + it has a radiator on it. Easy and nice upgrade. I also used a shrink tube to cover buck converter. https://www.aliexpress.com/item/1005006731079181.html?spm=a2g0o.order_list.order_list_main.328.1b171802RWcfGA
In the next update the psu fan will be controllable with potentiometer as well because it's a bit to fast. I decided to hide the knob under the nebula pad. You could place it where you like. But the end result of the knob looks like it came like this from the factory.
 

Update: 2024-06-16 - Changed the fan to Sunon maglev 6025 24V 3800rpm.https://www.aliexpress.com/item/1005006376145263.html?spm=a2g0o.order_list.order_list_main.346.1b171802RWcfGA . Picked up the cheapest one I could find (4.5euro) so my fan might not be genuine. I needed to change the connector from 3 pin to 2 pin as well. Other maglevs are usually 2pin. 
Unfortunately I can't compare to original fan sound, but it is much much quieter than the winsinn fan. 

According to creality wiki page the original fan is 6015 2000rpm, but the bearing or something else is making strange noises. (at least for me) The same goes for the stock PSU fan I think. That's why I will change it to maglev 6015 and will update this post.

(ORIGINAL POST BEFORE UPDATES) To install this cage you need to remove metal plate from the printer and cut a hole in it. I fixed it in place with hot glue. I ordered a winsinn fan from ali express. 6025 dual ball bearing 24V. It moves a lot of air but man it is loud. (5000rpm on 24V). It has the same connector as the previous fan so “plug and play”. 

I printed it with cr-petg.
15% infill
4 walls 
0.2mm layer height
normal auto supports

If you're wondering about the heatsink, it's for the bed motor.  nema 17 4x4x1.2cm . https://www.aliexpress.com/item/4000147159422.html?spm=a2g0o.order_list.order_list_main.376.1b171802RWcfGA . Some sticky thermal pads are also needed to install them. You can use these heatsinks for all 3 motors. Don't buy with adhesive.

Also I would recommend to install a dust filter for the cage. Best source ali express. I bought a roll of it for couple of euros.

You need to raise printers feet to install this mod.

This mod definitely voids your warranty so do this at your own risk.