My time bandwidth is entirely too sunk into other pressing matters these days to be able to take on 3D printing, but Some Day Soon, I want to set it up in my workshop. These large artifacts that could be mass-produced cheaper are not my target use case, however.

In our current throwaway-oriented manufacturing and product distribution civilization, it irks me to landfill perfectly good objects for want of a very small plastic part. It isn't the gross materials cost compared to the mass-manufactured cost that I evaluate in these situations, it is the logistical tail externalities cost I impose upon my descendents for landfilling objects that could be used with a modest (to my income level) investment in repairing it. This observes the "Reduce, Reuse, Recycle" mantra by reducing the waste stream through repairing.

There is a rant embedded there, on waste streams are a sign of technological backwardness as a riff on Iain Banks' "money is a sign of poverty", but that's for another time.

A couple of examples to illustrate.

A door bell ringer that has a base mounted to the door frame and then the housing slips over the base and latches in with a simple catch in the base. The housing was ripped off the base (toddler Destruct-O-Tron), and upon inspection it was the simple catch that tore off. The catch is the size of a fingernail clipping. It's long gone.

Customer service at the manufacturer was sympathetic, but unable to help; they acknowledged they had the bases, but it just wasn't in their procedures to send it separately even if I was willing to pay for it. If I have a 3D scanner+printer, I could create another base with that catch, instead of ordering an entire ringer and landfilling a working ringer for want of a fingernail-clipping size piece of plastic. When I ordered the replacement ringer, I not only threw away the plastic, but also the PC board (though I salvaged the battery), and contributed my small part to converting nasty bunker fuel oil into emissions and engaging the exhaustively long supply chain it took to create the replacement ringer (including a few drops more oil to create the virgin plastics that went into the new ringer).

That's just me, but multiply by billions of people making similar decisions over the next few decades as a burgeoning global middle class arises from the externalities wreckage wrought by our current globalization implementation, and it gets ugly fast.

Another example. A sippy cup is designed with a small plastic rocker at the top that lets a straw flip up and down [1]. That rocker can be pried off, and eventually is lost somewhere in the house until a few years later when it is found in some nook. Without the rocker, the cup leaks when upside down. The manufacturer has stopped making the product, in favor of a new version with an incompatible rocker; this manufacturer turned out to be willing to ship just replacement rockers, but they only had the new style on hand. Off to the landfill the cup goes, and I order replacement old style cups from dwindling retailer inventories. Unless I have access to a 3D scanner+printer.

The state of technology is sufficient as-is today to let me more than satisfactorily solve these situations without resorting to a replacement purchase, and about 1-3 instances come up every week. Double that occurrence frequency if I got a metal laser sintering 3D printer. I could refine various products with small, custom silicone bumpers/insulators/grips/etc. by creating silicone molds with a 3D printer. The applications only increase as the 3D printing technology advances. These are only the simple, obvious applications; much greater changes and improvements in industrial product design, manufacturing, externalities reduction, sales, marketing, support and distribution lie ahead when we combine these immediate applications to other developments.

[1] http://c3.q-assets.com/images/products/p/mc/mc-083_1z.jpg