Exactly. But you can find usable 3D printers for under $100 these days, so it still represents a lower barrier to entry compared to using a lathe & mill even before you consider the different skill levels needed. (CNC isn’t as simple as loading a file and pressing “go,” but it isn’t as complicated as machining, either. At least not unless you’re designing your own CAD models.)
Your local county extension office and nearby universities with agricultural programs.
Example: https://extension.uga.edu/publications/series/detail.html/71/home-garden.html