blex_jet - 5015 blower fan duct for BIQU H2

thingiverse

## blex_jet 5015 - v02_2022 ---- This is a cooling fan mount and duct for the BIQU H2 (v2 and v1) extruder, pictured on my Ender 5 Plus It is designed around a couple of principles: ##### Effective Cooling I believe the function of a cooling fan is to cool the layer beneath, not only the molten plastic currently being deposited. As such, the duct has a wide jet to allow cooling of a large surface area; a gentle choke upon entry into the duct to encourage (relatively) laminar ('smooth') air flow without compromising static pressure; and, considering the space available, a long aligning duct to direct the airflow. The cumulation of these properties results in a duct that is particularly good at preventing warping corners and cools overhangs and bridges wonderfully. Airflow is directed so the top of the airstream hits the molten plastic exactly as it exits the nozzle. Since the airflow is thick (2mm), and wide (12mm) the surrounding area is also effectively cooled. I do not believe omni-directional airflow is necessary. ##### Easy Printing The design has been tested for printability on nozzles up to 0.6mm, and can even be printed successfully in PLA without any part cooling fan if needed. A layer height as coarse as 0.5mm should be perfectly acceptable. No layers require small, difficult or high detail movements. The model is supplied in the correct printing orientation. Supports are required in the fan entry port (see photos with red arrows and gcode preview) , however they can be sparse and should be easy to remove. ---- Setup requires one M4 20-25mm bolt and nut with washers (or flanges) to attach the fan, and 2 M3 5mm-8mm bolts (washers recommened) to attach the unit to the H2 extruder. In the future, I hope to release a fully parametric version of this model to accommodate different heater block setups (e.g. volcano) but for now, the model is provided as is. This project was designed in [FreeCAD](https://www.freecadweb.org/), and I've provided the project files for anyone who wants them. . Successful Printing! Blex .