The part cooling fan on the CR-6 is quite noisy at full speed. This week we have been designing an adapter so that one of our quieter 40x40x10 mm fans can be used for part cooling.
We modified an existing design to fit the CR-6. It attaches to the head with two M3x10 mm screws (the holes used to fix the metal cover).
The adapter can be found here: https://www.thingiverse.com/thing:4736963
The CR-6 quiet fan kit in our shop has been updated so that you can add an extra fan to replace the part cooling fan.
Did you buy the kit before we added the part cooling fan option? The single 40×10 mm fan now has the option to include the needed screws!