Canted Cooling Fan Shroud for 40mm Fan

prusaprinters

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.) Print Settings Printer: Anycubic Kossel Delta Plus Rafts: No Supports: Yes Resolution: .2 Infill: 50% Filament: eSun PETG Black Notes: The shroud prints as oriented in the stl. It requires support for the duct, but no support is required for the screw holes. I printed in PETG for heat resistance and flexibility to snap around the cooling fins. Post-Printing The screw holes are sized to allow the M3 screws to cut their own thread. How I Designed This I debated on using an intake scoop or tilting the fan to accomplish a design to limit the intake of hot air. After reading a few papers on air cooled engines, I found that turbulent air flow across the fins is more efficient at cooling than a laminar air flow. I therefore decided to tilt the fan to increase the turbulence across the fins. My unscientific testing, so far, is showing that at least the cold end is cool. With the hotend at 200c, after 25 minutes the cold end stabilized at 71.6c. (Both measured with an infrared thermometer.) 4/12 Update: Just completed a 16 hour print. The cold end temperature 70.4c with the hot end at 195c. Category: 3D Printer Parts