UPDATE (9/21/2020) Updated the design to make the part thicker. Most parts now are 2mm thick vs the previous design of 1mm. Additionally I have added a light blocking panel to combat the buck converter's bright blue LED.

UPDATE (8/21/2020) I have updated the design to accommodate 15mm thick fans as they are a more common size than 10mm thick fans.

Hello Folks,

I got tired of the loud control board fan on the Longer LK4 Pro. This should be compatible with the LK4 as well as the Alfawise U30

I have designed this cover to house a 12v 80mm Slim Fan, the exact fan I used is linked however any 10mm or 15mm thick fan will do. I like the fan linked because it comes with extra wire connectors.

Amazon
https://www.amazon.com/gp/product/B005C31GIA/ref=as_li_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=B005C31GIA&linkCode=as2&tag=indianvillage-20&linkId=d08042afee38b062ea11a57deafd5450

The Cover also has standoffs to mount an inexpensive buck converter to power the 12V fan.The buck converter is powered using the original control board's pigtail and outputs the power directly to the fan. Be sure to adjust the buck converter to 12v

The buck converter used is
https://www.amazon.com/Regulator-Adjustable-Converter-Electronic-Stabilizer/dp/B07PDGG84B/ref=sr_1_2_sspa?crid=RQM80RFI3RPU&dchild=1&keywords=lm2596+buck+converter&qid=1626287123&sprefix=lm2596+bu%2Caps%2C185&sr=8-2-spons&psc=1&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUFDN0c1M085Sk9OVjcmZW5jcnlwdGVkSWQ9QTAyMzA0NDIzTDlIVlk2WU5OVDFYJmVuY3J5cHRlZEFkSWQ9QTA0ODg5MjAzSldQMzE0Sk9CQk5HJndpZGdldE5hbWU9c3BfYXRmJmFjdGlvbj1jbGlja1JlZGlyZWN0JmRvTm90TG9nQ2xpY2s9dHJ1ZQ==

The updated setup is significantly quieter than the factory setup. I have run overnight prints and there have been no signs of missed steps or overheating on the board.

To make this work some cable management will have to be done in the control box, as delivered from the factory the wiring situation is a bit of a mess. It took me 5 minutes and 2 zip ties to complete the cable management, see picture for cable management strategy.

The original screws are to be used to mount this printed cover.

See pictures for additional info.

It did take me a bit to design this. If this helped you feel free to toss up a like or post your make.
Happy Modding