As long as I can print myself a crossbow, I'll be happy. I assume the wood and sinew are not a problem, I'll just put a block of wood and a pig into the printer.

This is nice technology but I wouldn't expect the revolution just yet, it's going to cost a lot and the metal printer probably uses quite a bit of electric energy as well, so if every household had one we'd have to turn all the lights of to be able to use them...
Unless we plan to put a NPP into every town.