[RealDinosaur]

How long would it take to spin up an injection molding line?

Aren't there parts that exist that are easier to 3D print, due to overlapping elements or internal geometry which require additional manufacturing steps when using injection molds?

[systemvoltage]

Within 48 hours or less if there is a national emergency calling to get it done. The main time sink is CAD work to get the part designed, and then designing mold cavity and runners and getting the EDM die made, and running the EDM process to create cavity. The injection molding machine if run by a competent expert team - they already know most pitfalls of things such as rib/wall thickness, shot weight, run time and temperature for a particular type of plastic. You can run test shots and optimize the injection molding parameters in a very short time.

Alternatively, its possible to just use Aluminium molds for upto 10k parts.