I remember reading in an article that without 3D printing they could simply not get the cooling channel geometry they needed on the Super Dracos on Dragon 2. W

I remember reading in an article that without 3D printing they could simply not get the cooling channel geometry they needed on the Super Dracos on Dragon 2. Without 3D printing the combustion chamber they would need to use other cooling channel geometry, makin ghr engine heavier, bigger and less efficient.