Mk4S heatbreak exhaust duct

Following the discussion here,

https://forum.prusa3d.com/forum/english-forum-original-prusa-i3-mk4-general-discussion-announcements-and-releases/heatbreak-fan-might-be-causing-asa-abs-warping/

the heatbreak fan might be causing issues due to airflow around the model.

Since the influence on the Input Shaper by adding weight to the x-axis is not clear, I decided to design it as lightweight as possible, ending up with a calculated weight of 0.71g PETG.

Wall thickness is 0.87mm, following the recommendation of PrusaSlicer for thin walls with 2 lines at 0.15mm layer height. 

The design can simply be snapped onto the extruder, no need to disassemble anything!

Compared to other designes,  with this model the cross section of the air outlet is only reduced by a few square millimeters. Therfore impact on the airflow at the heatbreak should be negligible.

I recommend to move the X-carriage to the rightmost position by hand after mounting the part, to make sure it is not colliding with the threaded rod!

PrusaSlicer Settings:

Part is printed with front side down.

Plater

Supports: Everywhere
Infill: 15%

Print Settings

Profile: 0.15mm STRUCTURAL @MK4S 0.4 with:

• Layers and perimeters / Extra perimeters on overhang: yes (*)
• Support material / Generate support material: yes
• Support material / Syle: Organic
• Advanced: Bridge flow ratio: 1.05 (**)

(*) switch to Expert mode to get this option.
(**) 1st layers placed on supports do not look perfect so I tried this.

Filament Settings

Prusament PETG

Printer Settings

Original Prusa MK4S HF0.4 nozzle

Setup:

Material: Prusament PETG

Printedbed: Satin powder-coated sheet

Have a close look at the model before cutting off supports to avoid accidentally removing details requried for the snap-on mounting!
Due to the complex geometry, the part is quite fragile, take time to remove supports without breaking it.
 

1st layers placed on support do not look perfect so I tried to change params related to bridging. If you find better settings, please share it by adding a comment.

The MK4 version of this part can be found here: https://www.printables.com/model/876968-mk4-heatbreak-exhaust-duct