When Is It Better?

On one of the older entries, Roberto Michel writes:

Digital Fabrication is cool, but can it be used to produce actual parts, not just models or prototypes? Won’t more traditional methods like stamping, forging, or sheet metal fabrication, usually be cheaper for most parts?

To answer your first question, yes!  Digital fabrication has a reputation as something you only do for prototyping for a number of reasons, one of which is that many digital fabrication processes (especially high-detail powder sintering methods) produce chalky, delicate parts that you could easily crush in your bare hand.  Such parts obviously aren’t suitable for anything other than show and perhaps the delicate touch of someone who knows the part isn’t “a real one”.  However, this isn’t true for processes like the RepRap’s extrusion method, which creates sturdy, lego-like parts.  Many other digital fabrication processes can even be used as the starting point for processes which transfer the shape into more sturdy materials, like glass or even metals!

The realm of personal 3D fab presently means plastic parts that can be a bit fragile unless you have your machine well-tuned, but they’re definitely suited for everyday use.

To answer your second question, not always.  The cost of 3D printing scales linearly with volume.  For products where a really large number of parts is profitable, this is a complete non-starter.  But for hobbyists or niche markets, the linear scaling isn’t an issue.  All that matters is how much it costs to get one.  And in the case of a MakerBot or other low-cost extrusion systems, that cost is often on the order of pennies per cubic inch.  Acquiring the specialized molds and tooling for each new object would be prohibitively expensive in this kind of market.  And how small do I mean by niche?  Well, it doesn’t just depend on factory costs.  There’s all that shipping and handling too…

As the overhead cost of digital fabrication (both in money and time) goes down, the definition of “niche” here will widen.  There’s a whole class of everyday objects that can be replaced by existing low-cost parts, and since a 3DP owner using open source, non-lockchipped plastic can undercut the price of even cheap plastic items by cutting out a pretty big army of middlemen, we’re seeing extrusion material start to find its way into a lot of everyday items.  To put it in a short sentence with a lot of buzzwords, digital fabrication circumvents the need for sophisticated supply chains by leveraging ubiquitous computing to create a general manufacturing process at low cost.