05.02.2017 - ATTENTION: I no longer recommend this cooler!

06.04.2019 - I've removed all print files. Use this duct instead:

https://www.thingiverse.com/thing:2121279

I've been printing all kinds of coolers for my Anet A8 printer. Either some are too clunky, too heavy or some don't fit because they are too low or too high. With others the air for cooling is not being drawn to the ideal area on the object. Most of the ones I've tested are designs I made myself.
At the end of the day I have found that the cooler I designed for download here suits my needs the best. It has some similarities with this design which rightly so is the most downloaded version as I post this http://www.thingiverse.com/thing:1620630
However it didn't satisfy all my needs. The most important reason to design my own was that I have a different filament extruder height. Because of this I decided to design 6 coolers for different heights. They are 25.5mm, 24.5mm, 23.5mm, 22.5mm, 21.5mm and 20.5mm. You will need to measure the height from the bottom of the fan to the bottom of the extruder nozzle. See picture marked with "X". Then subtract at least 1mm to chose which cooler you want to print accordingly.
This cooler also has an opening for clearance of the heater cables.

Attention:

• The heater block is not centered on the ring. That is intentional! However it is important that the nozzle be in the center of the ring for even distribution of the air.
• It is recommended that the cooler be printed in ABS or PETG as these filaments are more heat resistant. However I have mine printed in PLA without any issues. When printing ABS or high temp filaments I just remove the cooler. You normally don't print with the fan on for high temp filaments.

Please let me know if you have a problem with the design so I can improve it if necessary.

Also please post a picture with comments if you have made one.

Thanks.

Leo