Fan mount, wind duct

Per makers request, I remixed my previous design of fan mount, wind duct from 4010 cooling fan to 4020 cooling fan.

The previous design is
https://www.thingiverse.com/thing:3256666
which has designs for
1 4010 cooling fan, 1 4010 blower
1 4010 cooling fan, 1 4010 blower, 2 sets add-on mounting hole.

1 4010 cooling fan, 2 4010 blowers
1 4010 cooling fan, 2 4010 blowers, 2 sets add-on mounting hole

For CR-X
1 4010 cooling fan, 2 4010 blowers
1 4010 cooling fan, 2 4010 blowers, 2 sets add-on mounting hole

Now, they are all with 4020 cooling fan mount.

Because CR-X is having different rounded hot end, so I'm establishing 4010, 4020 fan mount, wind duct as a different design.

A well designed fan mount + wind duct + add on provision for many 3d printer hot ends.

A good design must

Efficient on cooling
§ Hot end cooling duct conformed from fan blade circle to heat sink rectangle, making 100% air go through heat sink.
§. Filament cooling fan partially share duc