TorrentFreak, a blog covering happenings in the BitTorrent world, forecasts doom for some manufacturers when 3D printing becomes widespread. BitTorrent is a file sharing protocol often used for pirating digital media, most notably music, movies and ebooks. TorrentFreak focused on the scenario of replacing a sink plug by personal 3D printing and realized plug manufacturers (and most others by extension) could be in peril.
They propose that piracy damage to highly profitable media industries may pale in comparison to the thin-margined manufacturers. They say:
So, the trillion dollar question for the manufacturing industries will be how they plan to tackle the looming impact 3D printing will have on their livelihood and sustainability. Of course it’s worth noting that only a small portion of the industry will initially bear the brunt of the impact. Examples that come to mind include the humble plug I’ve mentioned, children’s toys, and building materials. I also wouldn’t mind a new protective shell case for my iPhone either. But not everything can be printed, so manufacturers who use materials that cannot be replaced by 3D printing will most likely be spared.
While some of this may come to pass in the distant future, the current state of 3D printing tech simply won't support these propositions. A mono-material plug could be created - if one was able to print with a semi-flexible material, but anything more complex is much more difficult to produce. Parts would require assembly, multiple materials, embedded electronics, availability of correct 3D models and other factors will surely protect manufacturing for a long time.
Besides, someone has to design and build the sink and plug in the first place anyway, don't they?