Simple airflow stub for Ender3 standart hotend metall case

This simple stub allow to remove parasitic airflow to the model from the hot-end fan.
This stub is installing inside a standard metal case. One side of the stub putted under the fan, resting on the other side against the carriage frame.
After stub installation, the air flow goes into the standard openings in the case on the left and a some little under the carriage frame, not touching to the printing model.

Stub printed from PETG+. Than more heat-resistant material, that better.