The household economics of 3-D printers

I have been a skeptic about the import of this new technology, but I am happy to pass along estimates to the contrary.  This is from a new paper by Wittbrodt, et.al.:

The recent development of open-source 3-D printers makes scaling of distributed additive-based manufacturing of high-value objects technically feasible.  These self-replicating rapid prototypers (RepRaps) can manufacture approximately half of their own parts from sequential fused deposition of polymer feed stocks. RepRaps have been proposed and demonstrated to be useful for conventional prototyping and engineering, customizing scientific equipment, and appropriate technology-related manufacturing for sustainable development.  However, in order for this technology to proliferate like 2-D electronic printers have, it must be economically viable for a typical household. This study reports on the life-cycle economic analysis (LCEA) of RepRap technology for an average U.S. household.  A new low-cost RepRap is described and the costs of materials and time to construct it are quantified.  The economic costs of a selection of twenty open-source printable designs (representing less than 0.04% of those available), are typical of products that a household might purchase, are quantified for print time, energy, and filament consumption and compared to low and high Internet market prices for similar products without shipping costs.  The results show that even making the extremely conservative assumption that the household would only use the printer to make the selected twenty products a year the avoided purchase cost savings would range from about $300 to $2000/year.  Assuming the 25 hours of necessary printing for the selected products is evenly distributed throughout the year these savings provide a simple payback time for the RepRap in 4 months to 2 years and provide an ROI between>200% and >40%.  As both upgrades and the components that are most likely to wear out in the RepRap can be printed and thus the lifetime of the distributing manufacturing can be substantially increased the unavoidable conclusion from this study is that the RepRap is an economically attractive investment for the average U.S. household already. It appears clear that as RepRaps improve in reliability, continue to decline in cost and both the number and assumed utility of open-source designs continues growing exponentially, open-source 3-D printers will become a mass-market mechatronic device.

I don’t see the twenty products a year as coming true, given the current limitations of the printers, plus there are significant start-up costs for learning how to run and fix the printers.  I still despair at the paper printer we own, which breaks periodically in a non-transparent manner.  What does it cost to have a plumber remove a simple hair stoppage in a drain these days?  And how much does one have to pay for the IP rights for what one prints?

Still, I am happy to reproduce one economic case for the import of the technology.

For the pointer I thank Sami Varma.