Trachea (hollow) from

thingiverse

Based on viktor3d's 'breakapart' of the Dusseldorf larynx model, I experimented in Tinkercad and successfully removed the transverse plate blocking the trachea from being a tube. The little nubs from the thyroid cartilage remain in the cricothyroid joint facets but come out easily. Best printing results occur at 60 degrees as specified in the file; the supports behind the trachealis muscle are much simpler to remove. Some supports remain in the middle, but this is not as difficult as printing it vertically or horizontally with the plate still intact.