Circular fan tunel for Anycubic Mega Zero.

Disclaimer: original fan tunnel work better on bridge test ! (Created for test purpose,new designs are in development)

New update more effective: https://www.thingiverse.com/thing:4460170

Printed without any support material.
If you have warping problems, you can use some 0.2 mm disc to help the model to stick to the build plate. (STL File: Support disk tab.stl) A photo shows how to position them.

As you can see, this gives very good results on the 3D Benchy (0.3mm layer height & 50mm/s default speed on Benchy)

No

No

0.15mm

30%