3d metal printing, especially sintering machines, circumvent so many manufacturing expenses and hurdles that it can only take off. Just think of how many machines, tools, and employees you need to manufacture something like an impeller, for instance. Additive machines also waste no materials, unlike Lathes, Mills, 4-axis CNC machines, etc. The complexity and intricacy of parts they can produce is unachievable on traditional machines. I've seen a DMLS machine produce every component of a turbocharger. Traditional methods would entail a forge, casting molds, 4-axis CNC, lathe, balancing machines, etc. That doesn't even include the salaries of the people to run those machines and the material expenses. It's pretty amazing stuff. Right now the primary limitation of these machines is their speed; most find their place in prototyping. I believe they start around 300k and the quicker machines are 1MM+. Not a huge threat to traditional manufacturing right now, but all the money in the industry is being funneled into fixing that. Every few years I check in on the cost and it's always falling.