ALMOST free
(email address required)
Minimus Hotend Cooler system is a 3D printable mod for most Ender 3D printers (and several others) that improves the efficency of the hotend and parts cooling with out adding weight to the moving parts.(in the basic setup)
Good explanation here.
https://youtu.be/uZ2NJfgmYYU
The designer has decided to open it up to the community to encourage modification to suit other printers, and improve the system in general.
.blend files are included in the package.
If you are like me and think this is a generous offer please thank the designer with 5 stars on Cults.
Ooh, I was just thinking about putting a cooler on my Ender 3 V2. Ill give it a slash