Kingroon KP3S Pro V2 fan duct

Recommended to print in PETG, you can try other materials but I have no experience with ABS or PC.

0.2 mm layer height, 0.4 mm nozzle.

To get the minimal material used, print with: 

• 2 walls
• top and bottom 1 mm
• lightning infill 1%
• default style tree supports with threshold angle 15 degrees
• block supports for the 2 screw holes on the back of the manifold and top of left duct (not required, see picture for example)

It is extremely important that the branches of the tree supports supporting the duct print properly so that the duct outlet is properly shaped. The model will be mostly hollow but I assure you it isn't necessary and will cut down on the weight a lot.

Water surface test shown at 0%, 25%, 50% and 100% fan speed.

Edit 14/8/24: added v13 (black in picture) (v12 in green in pictures), modified internal duct geometry for less restriction.

Started off with the model for the original fan ducts without M3 heat inserts by 8jack. The original model required bridging inside the manifold, as I was using PETG, it doesn't bridge very well and the internal geometry was too complex for it to bridge well anyway. I also felt it was unnecessarily big and used more material than it really needs, as well as being assymetrical when assembled onto the printer, protruding out more on the right side (ABL probe side). The duct outlets were also too big for my liking and the focal point of the 3 ducts did not align with the hotend nozzle in the Y-axis of the printer based on water surface testing. The ducts also blew to the sides of the nozzle tip rather than closer to the nozzle tip. Additionally the distribution of the airflow was more biased to the left duct compared to the right duct.

To fix the listed issues, the manifold was modified such that the model is printed at 45 degrees instead, this reduces the amount of support required printing the side ducts and eliminated the need for excessive long bridging inside the manifold. The amount of material usage overall was reduced as well. The manifold was also made to be symmetrical and not protrude as much from the hotend body (60mm wide, the hotend body is ~55mm). The duct outlets were also modified to be smaller and focused more closely to the hotend nozzle. The splitting of the airflow was inspired by the manifold design used by Brozu3d. The airflow is still slightly more biased to the left duct than the right duct but the effect has been reduced (and may require much more complicated tuning than I am capable of).