Update: I recently upgraded my hotend to a genuine E3D-V6 Full Metal Hot End. I found that using the 40mm Noctua fan was insufficient to prevent heat creep. There were three symptoms that cleared once I installed the 30mm fan which was supplied in the E3D-V6 kit.

• A faint clicking sound that came from the hot end during the retraction prime of the extruder.
• Under extrusion after a lengthy travel. Even though there was no stringing or oozing.
• Over extrusion following the under extrusion for about 5 millimeters.

My testing ranges in the slicer were:

• Hot end temp: 200c - 215c
• Retraction distance: 2.0mm - 3.0mm
• Retraction speed: 25mm/s - 35mm/s

The E3D specifications state that the fan's capacity must be between 4-5 CFM. Noctua's spec states that their fan's output is 4.5 CFM. But the 30mm E3D fan pushes a lot more air.

This is a fan shroud for the cool end of an E3D-V6 style hotend assembly. The fan is tilted up to reduce ingress of the heated air from the bed and heat-block into the air stream. I never noticed the issue with the original 30mm fan but it is evident after upgrading to the 40mm.

The shroud is designed around the E3D-V6 fan Duct and the Noctua NF-A4x10 FLX fan

Required Parts:

• 4 - M3 x 14mm Screws (I didn't have any, so I used M3 x 16mm.)