Ender 3 4020 Fan Housing

Model originally uploaded to Thingiverse at https://www.thingiverse.com/thing:3342107.

This part is based on the stock fan cover, but allows the use of a 4020 axial fan on Ender 3 and maybe other Creality printers. My original fan died after a couple of weeks. I'm now using a Sunon MagLev 40x40x20 fan which moves plenty of air and runs smooth and quietly, but wouldn't fit using the original fan cover.

I designed this in multiple parts to avoid the need for supports. Print with the fan intake hole down. Be sure to print the left bracket with a flat side down.

I left the intake hole open. You could mount a wire fan guard either by using longer M4 screws then mount the guard on the protruding ends of the M4 screws using locknuts, or by using 2 shorter M4 going into the unused fan mounting holes from the outside.

Parts needed:

• 2-4 M4 x 25mm screws for mounting the 4020 fan. (I only use 2.)
• 4 M3 x 8-10MM screws.
• The original 2 M3 fan cover mounting screws or 2 more M3 x 6mm.
• The original 4 part cooling fan screws or 4 M2 socket cap screws. I believe the stock screws are 2 8mm at the top and 2 10mm at the bottom (where the duct mounts).

Assembly:

1. Mount the top bracket to the fan housing using 2 M3 screws.
2. Mount the left bracket to the fan housing using the 2 stock M3 cover mounting screws or your own M3 screws.
3. If the screw holes are tight you may get bulges around them where the housing mounts to the metal bracket. If so, trim them and any other bumps using a razor of a file, so that the housing will mount flush with the bracket.
4. Do the following 2 steps in whatever order works best for you. I Installed an inline connector for my 4020 fan, so I install it first and then plug it in as the last step.
5. Mount the 4020 fan into the fan housing. Make sure it is oriented so that it blows inward.
6. Mount the stock part cooling fan (don't forget its 90° duct) to the right side of the fan housing. You could also do this after mounting the housing to the printer, but my wires are long enough that I can do this with the fan housing laying on the bed.
7. Mount the fan housing using M3 screws.