Ender 3 KE Silent Fans Upgrade

Welcome to this guide on upgrading your Ender 3 V3 KE 3D printer for a quieter and more efficient printing experience! If your printer is situated in a workspace where noise levels can be a concern, this project will help you significantly reduce those bothersome sounds. By replacing the stock fans with high-quality Noctua fans and optimizing airflow, you can enjoy a much quieter printing environment.

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For This Project, we need

Hotend Fans Upgrade

• 3D Printed Hotend Shroud that you can get from Cults: https://cults3d.com/en/3d-model/tool/ender-3-v3-ke-axial-fans-hotend-shroud
• 3 Noctua Silent Fans A4 40x10 mm, rated at 24V so you don't need to step down the voltage: https://www.amazon.com/-/en/dp/B0CN39MCPL/
• 12 M4x16mm screws
• M4 Nuts or Heat Inserts:The shroud comes in two types, one with heat inserts and one with M4 nuts. Depending on the one you choose, you will need 12 M4 nuts or 12 M4x4mmx6mm heat inserts.
• 3 JST Wires with a pitch of 1.25mm if you don't want to cut the connectors of the stock fans.

Mainboard and PSU Fans Upgrade

• 3D Printed Parts and Templates that you can get from Cults: https://cults3d.com/en/3d-model/tool/ender3-v3-ke-silent-fans-for-psu-mainboard-kit
• 2 Noctua Fans A9x14mm or A8x25mm
• 2 Buck Converters to turn the printer's 24V to 12V
• 2 JST Connectors if you don't want to cut the stock ones
• 8 M4x20mm screws and nuts, or you can use the rubber pegs included with the Noctua fans

WARNING: Before upgrading the printer, please note that opening and manipulating it will void the warranty.

To address the noise problem, let's first analyze where the noise comes from. After examining the machine with a noise meter, we found three sources of noise:

1. Mainboard and PSU Fans: This noise source is present as long as the printer is on. In an idle state, the electronic fans produce an average noise level of 55 decibels.
2. Heat Break and Part Cooling Fans: These fans produce an average noise level of 65 decibels when running at full speed.
3. Movement of the Y and X Axis: The KE printer comes with a linear rail on the X axis, which is very quiet. However, the bearings on the bed are not of good quality and make a lot of grinding noises, reaching up to 83 decibels when moving.

To disassemble the original hotend shroud, use an Allen key to unscrew the three screws of the stock shroud.

After removing the shroud, unplug the three fan connectors. Be careful: the connectors are probably secured with hot glue. Use unsharp pliers to remove the glue before disconnecting the fans.

If you choose to use the shroud with heat inserts, use a soldering iron to push the inserts into the holes of the 3D printed part.

If you prefer to use the M4 nuts variant, simply push the nuts into the slots.

The Noctua fans don't come with the necessary connectors for the 3D printer, so we need to solder the matching JST 1.25mm connectors to the Noctua fans.

You can cut and reuse the connectors from the stock fans, or you can buy new ones.

WARNING: If you buy new connectors, check that the polarity matches that of the stock connectors. Otherwise, you can damage the fans or the printer.

If your connectors don't match the polarity, you can use a needle to lift the connector tab and switch the wires.

Now we need to solder the JST connectors to the Noctua fans.

• Cut the Noctua fan wires and the JST wires so that you will have a total length of 12cm for two fans and 6cm for the third one.
• The Noctua fan has 4 wires; we only need the yellow one as positive and the black one as ground. You can cut the other two or tuck them away.
• Put some heat shrink tubes around the wires and solder the Noctua wires to the JST ones. Then, secure them with the heat shrink tube.

Let's attach the fans to the shroud:

• Check the Airflow Direction, Look for an arrow on the side of the fan that indicates both the rotation direction and the airflow direction.
• On the right side and the middle, use a 12cm wires fans and thread its wire through the hole in the shroud.
• For the left use the 6cm fan as this fan is close to the connector.
• Position the fan so that the airflow arrow points towards the air duct.
• Place the fan grid on the fan and secure it with 4 M4 screws.

After assembling the shroud, follow these steps:

1. Plug in the Fan Connectors

  - Connect the middle heat break fan to the heat break plug.

  - Connect the other two fans to the part cooling plugs.

  - Thread the right fan wire behind the heat break block.

2. Position the Shroud

  - Carefully place the shroud in position, making sure not to pinch any wires or allow any wires to touch the hotend or block the BL-Touch probe.

3. Secure the Shroud

  - Use the stock screws to secure the new shroud in place.

WARNING:In this step, we will be opening the case of the printer, which contains live electric wires. Please turn off and unplug your printer before opening the case.

Additionally, the motherboard is very sensitive to static electricity. I destroyed mine while handling it, so avoid touching the mainboard directly. Use anti-static precautions if you need to handle it.

The PSU and motherboard fans operate at 24V, but the Noctua fans operate at only 12V. Therefore, we need to step down the 24V to 12V using buck converters. 

To get 12V from the buck converters:

1. Connect the Buck Converters: Hook them up to a 24V power source. I am using a bench power supply, but you can use the 24V from the printer itself.

2. Adjust the Output Voltage: Using a multimeter to measure the output voltage of the buck converter, turn the potentiometer until you get a 12V output voltage.

Use an Allen key to unscrew all the lower plate screws, then carefully remove the plate until you can access the mainboard fan connector.

Use blunt pliers to remove the hot glue securing the fan connector and unplug it. Be careful not to touch the mainboard, as static charge can damage it.

Finally, remove the mainboard fan from the lower plate.

Now we need to drill some holes in the lower plate to allow for better airflow and to mount the larger Noctua fans.

1. Use 3D Printed Templates:

  - Secure the templates to the lower plate using M3 screws and nuts in the middle holes of the templates and the stock air holes.

2. Remove Rubber Feet:

  - Use a cutter to remove the rubber feet from the lower plate.

3. Drill the Holes:

  - After securing the templates, use a 3mm drill bit to drill the air holes and a 4mm drill bit for the fan mounting holes.

  - Drill a 4mm hole near the wire exit of each fan for the fan wires.

4. Mount Buck Converter Holders:

  - Place the two buck converter holders and use them as templates to drill holes for mounting them.

5. Clean and Deburr the Holes:

  - After drilling, use an 8mm drill bit to clean and deburr the holes.

To remove the stock fan from the PSU, follow these steps:

1. Remove the PSU from the Printer:

  - Unscrew the 4 screws located under the printer's bed to detach the PSU.

  - Carefully lower the PSU out of the printer's case.

2. Open the PSU:

  - Unscrew the 4 screws securing the PSU cover. Note that one of the screws may be hidden beneath a label.

3. Remove the Stock Fan:

  - Carefully lift the PSU cover.

  - Unscrew the two screws holding the fan in place.

  - Unplug the fan and remove it.

WARNING: When soldering wires, please double-check the polarity. I learned this the hard way by blowing two buck converters before realizing that the PSU wires' polarity was reversed.

To get the PSU fan wire to the outside, drill a hole on the side of the PSU, as shown in the picture. Be careful and clean all drill shavings from the PSU, as they can cause short circuits and pose a fire hazard.

I connected the JST wire to a quick-release connector so that I can remove the base plate without needing to unplug the connector inside the PSU.

After threading the JST wire through the drilled hole on the PSU side, close the PSU using the original screws.

Before mounting the PSU fan on the lower plate of the printer, follow these steps:

1. Prepare the Fan Wires:

  - Cut the fan wires to the desired length.

  - Place the 3D printed wire protector around the fan wires to prevent them from being cut by the sharp edges of the plate.

2. Thread the Wires:

  - Thread the wires through the hole designated for them.

  - Position the fan adapter and place the fan on top of it, ensuring that the airflow direction is set to blow air into the case.

  - Finally, cover the fan with the 3D printed grid.

3. Attach the Fan:

  - If using screws and nuts to attach the fan, you will need to drill some holes on the PSU cover for the screw heads to fit, due to the limited space between the PSU cover and the lower plate. 

   - To do this, place the lower plate in its position and mark the fan holes on the PSU cover.

  - Alternatively, if you are using Noctua fans, you will receive silicone mounts that allow you to attach the fan without drilling the PSU cover. These mounts can be compressed between the PSU cover and the lower plate.

4. Repeat for the Mainboard Fan:

  - Follow the same steps for the mainboard fan.

After preparing the buck converters and mounting the fans, follow these steps:

1. Position the Buck Converter Holders:

  - Place the buck converter holders near the wire entrance of each fan.

2. Solder the Fan Wires:

  - Solder the fan wires to the output terminals of each buck converter.

3. Solder PSU and Mainboard Fan Wires:

  - Solder the wires coming from the PSU and the mainboard fan to the input terminals of the buck converters.

4. Secure the Wire Protector:

  - Secure the wire protector with some hot glue to ensure everything stays in place.

As always, be careful with the polarity to avoid damaging components.

Finally, follow these steps:

1. Connect the PSU Fan Wire:

  - Connect the PSU fan wire to the wire coming out of the PSU.

2. Connect the Motherboard Fan Wire:

  - Connect the motherboard fan wire to the JST connector on the motherboard fan.

3. Close the Printer Case:

  - Carefully close the printer case. While closing it, check to ensure that the buck converters are not touching any thin parts inside the printer. If they are, remove the plate and reposition them.

4. Check Cable Positioning:

  - Ensure that the printer cables are positioned as they were originally to avoid any interference or damage.

By following these steps, you’ll ensure that all components are properly connected and positioned, allowing for a smooth operation of your upgraded printer.

The new fans are located under the printer, so you'll need to lift the printer slightly to allow air to circulate. Follow these steps:

1. Lift the Printer:

  - Use some double-sided tape to secure the 3D printer feet extensions to their original positions on the lower plate.

2. Attach the Original Rubber Feet:

  - Glue the original rubber feet inside the 3D printer feet extensions.

3. Alternative Solution:

  - In my case, I used thicker rubber pads to reduce vibration. You can also use this method by cutting 20x20x40mm rubber pads and using them instead of the original rubber feet.

This setup will help ensure proper airflow and minimize vibrations for a quieter and more stable printing experience.

Following this video tutorial, I replaced the stock Y-axis bearings with linear bearings. However, this did not reduce the movement noise. The only effective solution I found for this issue is to print at a lower speed and with low acceleration settings.