To fit Noctura fans on the Ender3 head generally requires replacing the entire shroud, however in this design we don't and you can grab the file for it for free here:
First changing the control board from the original Ender 3 board (flashed after the rebuild for 420mm bed). For newest version with new stepper motor drivers which is the main key. Additionally it's already flashed with a bootloader so all that headache goes out of the window.
Before the mainboard was changed I would average 60-70dB depending if the printer was going straight or printing arcs. Now after the mainboard change and all the stepper motor noises gone entirely its a cool 45dB average!
That is a 25dB - 30dB reduction is sound, which is insane.
I've created a 2 part mount that first screws into the original duct fan mounting points on the metal shroud. Then attached the nozzle to the bottom of the Noctura using the Noctura anti vibration cords.
Now the side fan connector is soldered and both labels marked with what each lead is.. handy for the future. Also able to disconnect at the head end without pulling the whole wire through ever again.
BEFORE connecting the fans each buck convertor needs stepping down from 24v to 12v. When you power the printer on only the head fans spools up without printing. So fastest way is to use that lead to adjust the first buck convertor. Turn the printer off, connect the next buck to the same lead and repeat again for 3 buck convertors all ready at 12v.
Before you can mount the fans we need to drill out the mounting posts from the back - through the front with a 1 <> 1.5mm bit. This is smaller than the M2 thread so you won't damage the thread. Then from the front end use a 2MM bit and slowly push until you break through, leaving the threads in tact.
We can now use the original fan bolts to mount the Noctura by sliding the bolts through the back mounting points and sliding the Allen Key through the first hole to tighten them. That's it, job done for the front, no special mounting required.
The side mount piece design first bolts into the top 2 original mounting holes that used to hold the duct fan. Then the Noctura with nozzle attached can be installed using the provided self tapping bolts from the Noctura kit.
The anti-vibration mounting straps will need trimmed below. Once done the new cooling setup is complete, remount the shroud exactly where it was before.
Initial placement of all the Buck Convertors, not the best but for initial testing it'll do. Note there is 3M tape holding them there and isolating them from the frame... don't just place them there as the Buck convertors do have solder points on the back of them!
Bed level view to show clearance between the bed and the fan nozzle on the side. It sits 5mm higher than the print nozzle so should always be out of the way.
Now I'm back up and running I was able to print up some cases for the buck convertors. I wanted a better isolated mounting, so this just lets them sit exactly where I can see them if I need to. Again 3M double sided thick tape is used to mount the Bucks inside the case and the case to the frame itself.
While I had the printer out I got a webcam installed and have had a collection of smaller models/figures in a draw for a while. Quickly knocked up some shelving using 5mm foam whiteboard so I can see them from outside the enclosure and while printing. The higher the rail goes the more shelves you see above.
To fit the new Noctura fan which is thicker than stock means outside the case. I don't want restrictions on airflow so I've removed the metal stamped grill area and filed the edges.
Remember to repeat the same process, adjust the buck convertor down from 24v to 12v BEFORE plugging the fan in. I've used the same buck enclosure as before to ensure its isolated from the PSU housing. 3M thick double sided tape used to mount.
The final end result is now 33dB ! Thatis a massive reduction from stock sound levels. Its super quiet to the point if the webcam and light weren't on then I'd barely know it was printing at all!