Pandora's Millions is the title of a George O. Smith short story. Along with the preceding Special Delivery, it is one of the earlier explorations of an approaching and largely unheralded future; for an even darker take, try Damon Knight's A For Anything.* (The relevant Smith work is The Complete Venus Equilateral and you can find 'em at Amazon via Tam.)
Oh, we haven't quite got Knight's "Gismo" yet, though "listeners-in" could most certainly end up with copies, as Mrs. Channing muses in the Smith yarns. But an ever-growing group of hobbyists have been steadily pushing on with the next best thing -- and possibly the best "next thing" to come along in decades: 3-D printing. If it's small and can be made of plastic, it can be printed while you wait.
As things stand right now, a 3-D printer can't print a copy of itself -- though they're closer to that goal with every day. AR-15 magazines are being developed by many designers. It doesn't stop there: local blogger Shermlock Shomes recently linked to a printable AR-15 lower. That might need some help in the way of reinforcement and threading, but it's one more step. Hacking away from the other direction, CNC machining is working its way down to near-desktop hardware. It's already garage-scale -- and already making happy bangity sounds. CNC laser and plasma cutters will let you cut out anything you can model as a collection of flat sections, too; I've linked in the past to online services that will carve out your design or sell you the interesting things designed by others.
For a lot of basic manufactured items, everything except microchips or light bulbs, the old assembly-line model is already dead; it's just tottering on for now. The future is catching up and it doesn't need a factory at all. And if you can print whatever object you want, you're wealthy in a way no people have ever been before, ever.
The future? One word:
Mostly thermoplastics. Don't like that old lamp, that footstool? Toss 'em in the hopper and print up a spice rack -- or an AR-15 lower. (Thermosetting types are often tougher but single-use).
You'll probably have to rent time on a fancier machine to chew out the metal parts. At least for a few more years.
How you gonna keep 'em down on the farm when they can print out their own ride to town?
* Of course, if you're concerned about a Knight-type collapse, you may find Smith's Lost Art applicable. It's also in the VE collection.
STANCOR 10P TRANSMITTER: UPDATE 12
5 days ago