The ambition of the RepRap project (“replicating rapid-prototyper”) is undeniably cool: to design a machine which is essentially a self-replicating 3D printer. By building up objects layer by layer, rapid prototyping technology can be used to manufacture the parts for just about any simple object or machine. It would be like having your own little factory in exactly the same way that having a laser printer is like having your own printing press, except that you can use this little factory to make another factory to give to your friend.
Theoretically, desktop manufacturing technology then spreads exponentially, until everyone can make whatever material objects they need from downloaded plans, for only the cost of feed plastic.
The dream is best explained in this excellent little video:
It’s hard to overstate the fundamental shift that would come with truly widespread desktop manufacturing. Right now all of the objects we use are manufactured somewhere far away and shipped to us, and the designs are expensive and slow to change. Instead, imagine if everyone had a household appliance, perhaps fed by spools of plastic and metal wire, that could manufacture just about any object from plans downloaded from the internet. It’s hard to see how private designs could compete with millions of amateur object designers geeking out over their widgets for the benefit of humanity, which means that designs for all the basic desirable objects would be freely available.
Want a new phone? Download the latest Android phone plan from the Open Handset Foundation. That’s cool, but the really cool thing is this: everyone in the world could have one for the price of plastic. More to the point, everyone in the world could have e.g. irrigation pumps, car parts, light switches, medical devices, essentially all the trappings of modern technology.
It is of course debatable whether or not an increase in humanity’s use of energy-consuming technology is a good idea at this time. However, it seems to me unconscionable to deny it to the world’s poor just because we got there first. Further, one could also replicate the parts for home biomass reactors, electric cars, and other advanced energy devices — regardless of whether or not anyone can make a profit selling such items commercially.
New versions of the replicator with enhanced production capabilities (now with integrated circuits!) would be designed to be manufacturable using existing models. This means that manufacturing technology would itself spread virally. To bootstrap this, all you need are a few basic self-replicating machines, then the technology passes from friend to friend until the whole world is saturated and capable of producing all future upgrades.
But we are nowhere near that dream. There’s a lot of promise to desktop manufacturing, but I’ve come to believe that the RepRap approach is probably not the right one. And I’m going to try to explain why.