Ender 3 Pro fan cover for Noctua A4x20

thingiverse

I made this project for one single purpose : replace the original ultra-noisy hotend cooling fan of the Ender 3 Pro by the much quieter and efficient Noctua A4x20 fan. I wanted to keep everything else as is (with some minor adjustment) so original screws still work. Since I have a BL Touch installed on my printer, I made two versions of the support. Speaking of support, I don't like support in print since they don't produce nice and clean surface that I wanted for this thing. So the cover and the support of the cover are two separate things that you simply stick together with instant glue (ex. Gorilla super glue gel). Now about the fan. Yes, the Noctua is a 12v fan where the original is 24v. So you got to do something about it. I see a lot of people going the buck converter way but I find this cumbersome and a waste of money when a simple 50 cents resistor will do the job and is easy to shrink wrap and hide away (more easily then a bulky buck converter). I did the math for you and a 360 ohms, 2W resistor in series with the power connector will do the job. This will bring back the fan at is 12v operating voltage (check this link for the detail : https://ohmslawcalculator.com/voltage-divider-calculator ). I'm very pleased with the result and now my Ender operate at an average of 42 dB ( with all 4 fans running). I should mention that I also replace the PSU fan and the electronic case fan with Noctua counter parts and use the Creality Silent Driver board (v4.2.7). Now, my printer can operate at 5 feet for my desk and being able to do my Teams meetings without any problem. Finally, I made some measurement of the temperature of the heat dissipator of the hotend before and after the mod and I shove 4 degrees and it now run at 30 Celsius. UPDATE - 2021-04-12 ------------------------------------ Simply rotated the case in is printing position