This is Nicholas Weaver's second article on the military impact of the spread of technology.America owes a big chunk of its military superiority to what it can make the tools, facilities, and expertise needed to put together sophisticated planes, ships, and weapons. So what happens when much of the high-precision manufacturing behind Predators and F-22s can belocated anywhere and owned by anyone?The day isn't as far off as it might seem. Twenty years ago, if a designer wanted a new, high-precision part, he constructed a design and handed it to a skilled (and expensive) machinist, who would produce a prototype. If more than a handful of handmade parts were needed, an even more expensive set of tooling would be created.Today, the same designer develops his plan on a computer and then emails the design to the machine shop, which uses an assortment of CNC (Computer Numeric Controlled) machine tools to produce the prototype. CNC lathes can turn effectively arbitrary radially symmetric parts, cutters can create 2D shapes, and CNC mills can cut a 3-dimensional part to extremely tight tolerances. And as long as the designer only needs a few dozen (or even a few hundred) parts, the shop just feeds more material into the CNC machines and out pops more parts.All it takes is a few shipping containers, a power hookup, and a source of refined metal ingots to produce high precision parts and designs from a high-technology mobile factory. And if that doesn't seem like it's got much to do with the military, think again. A major reason why the AK-47 is a "Weapons of Slow Mass Destruction" is it's easy-to-make design. Any country with a factory base up to the low standards of Russia circa 1947 can stamp them out en masse and wreak havoc. Think of the possibilities when small jet turbines or piston engines for cheap unmanned planes become so simple that anyone can stamp them out and build their own drone air force.
CNC systems have become almost ubiquitous for manufacturing, from $2500 Sherline desktop mills (for a complete system including a linux computer and GPL software) to million dollar high-throughput systems with automatic material feeds.Anyone watching American Chopper has seen the CNC controlled water-jet used to cut custom wheels, with rims limited almost solely by imagination.The US Army is starting to exploit these fantastic tools, prototyping and deploying a mobile repair yard, the Mobile Parts Hospital, which, instead of keeping a large inventory of spare parts, is able to produce replacements on demand.The biggest limitation is one of design. Parts produced by forging, stamping, casting, or extruding can't necessarily be replaced using pieces made on a CNC mill. Clean-slate designs don't have this problem. If all the high-precision components were designed to use CNC-produced parts (with a conversion to higher-volume production techniques if necessary), CNC-replacements, and even entire CNC-based manufacturing are now straightforward.Which brings us back to transportable factories. Write a (large but reasonable) check, place a few CNC machines in a shipping container, add a couple of containers of refined raw material, and now anywhere the containers go a factory resides. Be it critical spare parts for a broken well, a replacement piece for an automobile or the critical components of a rocket motor, the same factory can make all three. A huge revolution for the majority of the globe which remains largely unreachable by FedEx.In the CNC world, proliferation becomes a matter of design, software, and materials, rather than finished systems. What happens when North Korea or Iran starts selling missiles as digital files rather than on ships which can be intercepted? When private designers and companies create designs which anyone can produce? Two words: Watch out.-- Nicholas Weaver