Introduction: Ender 3 - Silent Fan Replacement Guide

Disclaimer: This guide is no longer maintained, sorry!

Creality's Ender 3 is a good budget 3D printer and rightfully popular, but I guess everyone owning it can confirm:

Its not very silent. In fact, its pretty loud while printing at high or even normal speeds.

This guide will show you how to use 12V parts in a 24V print, replace the fans and install a new duct for part cooling from both sides.

Big thanks to Noctua for providing me with some of their high-end silent fans and 2print3D for sending me an new board after the Y-Driver died on mine (unrelated to this project)!

Supplies

Printable Parts

Ender 3 Noctua / Quiet Collection⠀on Thingiverse (Mirror here)


The Hotend / Part Cooler

For this guide, I used the BantaMount Beta from bantam.design
If you have problems downloading from the original page, try here:
Mirror #1 --- Mirror #2 --- Mirror #3

If you have an Stock Ender 3, choose CR10 - MicroSwiss / Stock and the Part Cooling / Modules you would like to use. Dual 40mm Fans is used from here on, if you choose something else or 5015 Blower fans, adjust accordingly.

Alternatives:

CR-10 and Ender 3 Hotends are the same, so you should be fine.

Other Parts

I used Noctua fans for this project, because they are well-known to be almost inaudible and a silent printer was the ultimate goal here for me. Their OmniJoin Adapter Kit that comes with the FLX versions of the fans saves us time by reducing the required soldering points and lets us use a regular fan plug, so we dont have to modify the Noctua fans them self.

But choosing Noctua presents us with 2 problems: Voltage and Connector Plug

The Ender 3 runs on 24V, but our fans are only rated for 12V.
The Noctua fans have a 3-Pin connector, but our Ender board uses 2-Pin fan sockets.

The first problem can be overcome by implementing Step Down modules, which convert our 24V source to and 12V output by adjusting them correctly. The second one is just solved by simply cutting and reusing the original connector. You might be able to source fitting 24V fans too, but they tend to be noisy.

You will need:

  • 1x 80x80x25mm Fan - e.g. Noctua NF-A8-FLX for PSU Cooling
  • 1x 40x40x10mm Fan - e.g. Noctua NF-A4x10-FLX for Board Coolung
  • 3x 40x40x20mm Fan - e.g. Noctua NF-A4x20-FLX for Hotend and Part Cooling
  • 4x Step Down modules, for example LM2596S DC-DC
  • Wires, thin ones like Arduino Jumper Wires should be enough
  • Electrical Insulation Tape and/or Shrinking Tubes
  • Selections of Screws, depending on the Hotend / part Cooler
  • MK8 Silicon Sock for your Hotend (optional, but recommended)

I also used 40x10 fans for the part cooling, but some headroom for more airflow by using the 40x20 instead might come in handy. But so far, my 40x10 seem to be enough too. If you have them already, use them. If not, buy 40x20 instead.

Tools

  • Soldering Iron
    You dont need something special or fancy, its just for soldering a few thin wires

    ⠀

  • Hot Glue Gun
    It won't be as janky as you think, I swear!
    ⠀
  • Screwdrivers
    A small flathead and (depending on your screws) a normal sized phillips head
    ⠀
  • Crimp- and Cable Tool
    Yes .. a normal scissor will also work just fine for removing some isolation from the wires
    ⠀
  • Multimeter
    .. or some other way to measure voltage. Dont skip this! You have to dial in the step down modules and the fan header on the PSU puts out different voltage depending on the batch you get!
    ⠀
    Maybe get a cheap Kit from a local retailer or Amazon like this!

Step 1: Use Stepper Dampers or Swap to a Silent Board

To really make a difference, you will need to have ether Nema Stepper Dampers or a Silent Board installed.
Its really to no use if you make your fans silent, but the stepper motors sing their song all the time you are printing ;)

Stepper dampers are dirt cheap, but you might need to buy heatsink and print new mounts too. You cant put one on your extruder or Z-Stepper, so retraction and Z-Hop is still pretty loud.

I therefor recommend to buy a Silent Board like the BIGTREETECH SKR mini E3 V1.2 !
Its nearly a drop-in-replacement and comes with all the bells and whistles you could want.
True Marlin Software, Thermal-Runaway Protection and BL Touch port! And it makes your steppers quiet, obviously.

Step 2: Replace the Power Supply Fan

This step requires you to open the power supply and measure voltage on 2 pins (which have either 12V or 24V) while its connected to mains voltage (120V or 230V)! If you feel uncomfortable doing so, skip this step and leave the PSU as it is. It shouldn't be dangerous, as you measure on cables outside the PSU itself and dont come into contact with the main power, but be warned anyway!

Unplug the PSU from power and flip the power switch a few times to discharge the remaining voltage. After that, disconnect the yellow XT60 connector under the heatbed, remove the screws attaching the PSU to the Z-beams and move your printer out of the way for now.

Depending on the model of your PSU, remove the remaining screws attaching the cover with the fan to the rest of the PSU housing. Lift the cover just enough to unplug the fan before trying to remove it completely. Be careful not to touch anything else!

Prepare your new printed cover by attaching the bigger fan and fan grill, leave the fan cable as it is for now. I kept the original airflow direction (blowing out) on my model, check yours and rotate the fan if needed. Blowing fresh air in seems to be the logical way to cool the PSU, but I guess they have a reason why they let it blow out instead of in. And we dont want it to blow up either, right?

Cut the original connector and wires near the fan, so you have as much cable es possible to work with. The 2 wires should be color-coded, red for positive and black for negative (ground). If they arent, you can check the labeling near the plug on the power supply PCB. Remove the insulation at the end of both wires, 0,5cm should be plenty.

Measuring the voltage on the fan plug is a bit tricky, so be careful and patient.
My PSU is labeled "S-360W-24-L" and controls the fan by switching between 2 modes: Load or Idle.
If the printer is heating or running, the fan voltage is set to 24V, if its idling the voltage drops to 16,4V on my model. Yours might be different, so dont use this a reference. Some batches of PSUs are running 12V all the time, others are temperature-controlled. To set the correct output voltage of our step-down module, we have to measure while heating! Get your Multimeter (or something else to measure voltage) ready, plug in the connector with wires you just cut off and connect the PSU with the printer via the XT60 plug. Set your bed temp to 70°C, wait a few seconds and measure the voltage on the fan wires while it is heating up.

Turn off the printer and remove the power plug from the PSU after you are done! If you are using Shrinking Tubes as insulation, dont forget to slide them over the wires now before soldering in the next step.

If its measuring 12V, you dont need a step-down module here, just solder the included fan plug to the wires.

If its measuring 24V, you will need the step-down module, continue with soldering red/positive to (+) Input and black/ground to Input (-) on your step down module. Solder the included fan plug to the Output side, again red for (+) and black for (-).Turn on the printer and measure the output voltage on the step-down module, adjust it by turning the small screw on the module with a screwdriver until you get a solid 12V.

Put everything together! Insulate the exposed wires and step-down module, find a nice spot for it and/or extra cables besides your fan and hotglue it in place. Plug in both sides of the step-down module and close your PSU up again. Secure the new PSU shroud by reusing the original screws and attach it to your printer again.

Good Job!

Step 3: Replace the Board Cooling Fan

This one is fairly straight forward and quick.

Remove the 2 screws in the front, move your bed to the front and unscrew the remaining screw in the back.
Move the bed to the back again, carefully lift the board cover and unplug the fan. Unscrew the fan, put in the Noctua and you are presented with 2 options to go from here:

  1. Keep the original internal wiring, which results in the board fan only running when the part cooling fan is running
  2. Wire the board fan to an static voltage on the board, so its runs all the time

Generally Option 2 is to be preferred, because board and stepper drivers are getting cooled all the time. If you are printing without part cooling, for example a large first layer, the stepper drivers can get quite toasty.
If you are using Shrinking Tubes as insulation, dont forget to slide them over the wires now before soldering in the next step.

Remove the insulation at the end of 2 extra wires, 0,5cm should be plenty. Add them to this terminal on the board by loosen the screw a bit, pushing them in under the small metal plate and tightening both screws again. If you have trouble getting them in, remove the screws holding the board and turn in a little to get some space.

Continue with soldering red/positive to (+) Input and black/ground to Input (-) on your step down module. Solder the included fan plug to the Output side, again red for (+) and black for (-).
Turn on the printer and measure the output voltage on the step-down module. Adjust it by turning the small screw on the module with a screwdriver until you get a solid 12V.

You can wrap the excess cable around the fan like I did, spares some space and helps to manage the cables.
Dont forget to insulate the exposed wires and step-down module!

Unplug the fan and put it together with the cover away for now, the next step require you to access the board.

Step 4: Replace the Part Cooling Fan

The part cooling fan wires are yellow (+) and blue (-) this time, double check yours just to be sure. It should be plugged in to one of the two controllable fan connectors, see here. Voltage (+) and Ground (-) is written on the board too. Creality is using Ground Side Switching to control the fanspeed, so we can't just solder in the step down module here!

If you are using Shrinking Tubes as insulation, dont forget to slide them over the wires now before soldering in the next step.

Unplug the fan, cut the original connector and about 3cm wire, so you have as some cable to work with. Remove the insulation at the end of both wires, 0,5cm should be plenty. Continue with soldering yellow/positive to (+) Input on your step down module. Blue/ground needs to be extended with some wire by the length of your step-down module. Input (-) from the step-down module has to be connected to ground. Should look like this !

Solder the original wires going to the Hotend to the Output side of the step-down module, again yellow for (+) and blue for (-).

Plug in the original connector, turn on the printer, and manually set the part cooling to 100% (255) and measure the output voltage on the step-down module. Adjust it by turning the small screw on the module with a screwdriver until you get a solid 12V.

Dont forget to insulate the exposed wires and step-down module before finding a nice spot for it besides the board.

Step 5: Replace the Hotend Fan

If you are using Shrinking Tubes as insulation, dont forget to slide them over the wires now before soldering.

Solder 2 wires to the Input side of the step-down module, loosen the screws from this terminal again and pull out the Hotend Fan cables. If they arent color-coded, make sure to mark positive and ground on the cables. Push in the wires from the step-down module you just soldered and tighten the screws again.

If you have done everything correctly, there should be a total of 5 wires in this terminal now:

> positive + ground from the step-down module for the Hotend Fan
> positive + ground from the step-down module for the Board Fan
> ground from the step-down module for the Part Fans

Solder the original Hotend cables to the Output side of the step-down module.

Turn on the printer and measure the output voltage on the step-down module. Adjust it by turning the small screw on the module with a screwdriver until you get a solid 12V.

Dont forget to insulate the exposed wires and step-down module before finding a nice spot for it besides the board.

Step 6: Assemble New Hotend / Part Cooling

Start by the removing the original shroud/cover until you have only hotend, heatsink and both fans left. Replace the Hotend thermal insulation with a Silicon Sock.

If you are using Shrinking Tubes as insulation, dont forget to slide them over the wires now before soldering.
Cut off the fans and solder 2 of the included fan plugs in parallel to the Part Cooling cables and one plug to the Hotend Fan cables.

Assemble the printed parts of your new Hotend / Part Cooling according to the instructions and attach it to the X Carriage. You can wrap the excess cable around the fans to clean things up a bit before plugging them in!

Plug in the Board Cooling fan too and screw the cover back in.

You are ready to do your first print now! Depending on the Fan Duct you are using, you might need to set an Nozzle Offset in your Slicer