Anycubic i3 mega bulky fan duct for Sunon radial fan

thingiverse

Made this modification to utilize the Sunon fan (Sunon Radial Fan 50x50x15mm MF50151VX-A99) for part cooling while installing it in the original Anycubic fanbox. This model was rebuilt from scratch, eliminating reliance on the fan housing to hold the duct in place like its predecessor but instead attaching with fan screws on both sides. The new design is slightly bulkier but still allows sufficient clearance (~2.5mm with default nozzle) to pass over the original build plate clamps and does not interfere with the x-axis reference switch. Mounting requires an additional hole to be drilled adjacent to the bottom one to accommodate the different screw distance of the Sunon fan, as opposed to the original Boosfan. A picture shows the left side of the cover with the fan duct attached and a blue arrow pointing to where the original fan mounting hole was. No supports are needed when printing since the top of the air ducts is constructed like a gable roof. Note: Similar to the previous fan duct, you will likely need to either drastically limit the fan speed or run PID autotune after replacing the fan and installing this duct, as this combination cools the nozzle more than the heater can compensate for with default PID values. Otherwise, the actual nozzle temperature will be significantly lower than selected (I've observed differences of more than 20°C without tuning the PID values), which may also cause the printer to abort the print with a heater error. Sunon fan: https://www.amazon.com/dp/B0177QGEPY