The potential of additive manufacturing has been a recurring theme on this blog. There is no denying that 3D printing is an intriguing technology that holds a lot of promise. To date, however, most of its applications have been in low volume settings such as making prototype parts or custom fitting items for medical applications. How do costs fit into that decision? I have yet to see a clear explanation of just how the variable costs of 3D printing stack up. Now the Economist provides at least a partial answer (3D printing scales up, Sep 7).
Additive manufacturing has other limitations. It can be slow—taking several hours to print, say, a body panel for a car. But speed is relative. What may be too slow for a large production run might be fine for a one-off item which would take weeks to make in a machine-shop.
Material costs are also high. Acrylonitrile butadiene styrene, better known as ABS, is the most common 3D-printing material. A mass manufacturer using plastic injection moulding might buy ABS in bulk for about $2 a kilo, but as a bespoke powder or filament for 3D printing it can cost as much as $80 a kilo, says Anthony Vicari of Lux Research, a Boston company that tracks emerging technologies.
In part the price difference is due to higher standards of purity and composition required for 3D printing. But mostly it is because 3D-printer manufacturers require users to buy materials from them and mark up the price, as with the inks for 2D inkjet printers. Mr Vicari thinks this strategy is not sustainable long term as third-party suppliers enter the business. Moreover, some big manufacturers, like GE, are developing bespoke 3D-printing systems which are not dependent on a single supplier of equipment or material.
So this backs up the idea that 3D printing has a high variable cost relative to conventional manufacturing techniques. The question is whether these are likely to change over time. The speed tradeoff seems unlikely to change much. If you are doing something in really high volume, conventional techniques like injection molding are very fast and super cheap — once the molds are made. The production speed of 3D printing may improve over time but it has a long way to go match injection molding and it is not even clear that it would be worth the investment to close that gap.
The question of material cost is a different story. Cost could come down by developing printers that are more tolerant of input imperfections. There could be pressure for that for a number of reasons. For example, developing markets with more limited, less robust supply chains could favor equipment that is less finicky. However, big buyers would seem to be as important. 3D printing equipment makers gain from selling to big established firms. Having a mainstream manufacturer like an automaker adopt your equipment is a feather in your cap and a marketing point to other firms. But it is hard to imagine that GM or another big producer is going to want to find itself beholden to an equipment supplier. That pressure should drive down costs.