The Ender 3 S1 has been a great machine so far except for the loud hotend fan.  I had a spare 4020 blower fan so I designed this bracket to replace the one found on the sprite extruder.  Even at 100% I've found it to be quieter than stock, but was able to reduce it to 50% fan speed for even quieter performance while still maintaining proper cooling.

You will need the following hardware:

3 x M3 16mm screws to mount the fan

You will also need to get the old fan's JST connector onto the new fan.  I simply clipped and soldered the cables.

It prints in 2 parts and supports are not needed.  After securing the bracket be sure to tuck the cables to allow the x limit switch to trigger. I'd recommend manually testing the triggering of the switch prior to homing.  The small clip at the bottom of the probe mount is to tuck the part cooling fan cable if needed.

Fan noise comparison video: 

20/05/2022 - Moved the probe mount up 2mm since it seemed unnecessarily close to the bed when stowed.