I have always seen the extruder fan more as a problem than as help. The fan does proounce warping and seems to make the 1st layer to detatch.

However, with access to a Sovol SV07, which is an insanley fast klipper printer, I was suprised to see that they are using a quit noisy and strong fan. So it was time to check if it really makes a difference.

Model

I have found a cool fan duct for the Ender 5 (does only work on the original 2019 model that I own):

• Fan Model Ender 5 Cooling Duct
• Warping/Curling Test

1. try - Base line test

with the original duct attached, I printed the test model at 300mm/s. It warped quite dramatically and was ripped off the build plate by the nozzle. Build plate temperature was 60°C.

2. try - fan duct on

Adding the fan duct, I started printing with 400mm/s. The fan started at the 2nd layer which lead the initial layer not sticking to the build plate on the edges. It was ripped off the build plate around layer 9.

3. try - a bit cozy

Because of adhesen proboems I changed 2 things:

• increased build plate temp to 70°C
• fan stopped until layer 4 to prevent adhesen problems.

This lead to a better result. there was still warping and the print came loose of the build plate at around layer 15.

Conclusion

This is a success. if the fan is not started too early, it has clearly improved the print reliabilty at high speeds.