Other than the materials that can be used, what limitations do lower-end 3-D printers have at this time?
Another limitation is accuracy. These machines don’t have the temperature control of higher-end systems, and consequently the dimensional accuracies suffer. The more expensive industrial systems take into account how much a part will change as it goes through the process of being made. Better temperature control enables a printer to better adjust for changes in the material as it is layered, solidifies and shrinks. If you don’t take those changes into account, some layers might be farther apart, creating voids that prevent the finished product from being as strong as it could be.
All of these things can be overcome. There are lots of people working in their homes on inexpensive desktop systems [like those MakerBot produces] who are going to be geeky, experimenting and optimizing their systems. They’ll write their own code and figure out how to compensate for their equipment and materials. That’s what my students do. There is some knowledge that you have to develop to use these systems optimally.
As inventors develop this knowledge, are there concerns that more of them will experiment with 3-D printed weapons?
3-D printing is not the only enabling technology here. 3-D printers may be a little less complicated to use than [some computer numerical control (CNC) systems that manufacturers use to make tools], but you still can buy a CNC machine today and use that to build weapons. In fact, I would be much more scared of people who have expertise in machine shops [making weapons] than I would of someone using a 3-D printer.
And, even if you don’t print the parts for the weapons yourself, there’s an entire industry that makes parts on demand today using 3-D printing. You can upload your file online without even speaking with anyone and pay for it with your credit card.
How soon will higher-end 3-D printers capable of using better materials become affordable for hobbyists and inventors?
I don’t know how much the cost can come down for some high-end systems because they are big machines and they use more expensive industrial components, which limits how much the price can be reduced. And the price of high-end systems may not be the limiting factor for hobbyists because they can take a desktop system [like those made by MakerBot] and supercharge it, and there’s no technical reason you couldn’t use it to print a weapon.
How would you supercharge a desktop 3-D printer to give it that capability?
I may enclose it so that I can reach higher temperatures and work with [stronger, more durable] materials. I might also do this by modifying the printer’s heater to make the printhead hotter.
People are less likely to modify an industrial system because companies like Stratasys don’t give you access to their printer’s source code. MakerBot and other desktop printer–makers do. That means I can write my own code to change things on these lower-end systems but I can’t [change] that on a Stratasys system. Even the materials used by industrial systems are controlled. A canister of material used in a Stratasys printer even has a microchip that knows what and how much material it contains.
What impact will Wilson’s experiment have on 3-D printing?
It concerns me a little, but I think this type of project was inevitable. We would all like these technologies to be used for the benefit of society, and I believe these benefits far outweigh the risks. There are lots of wonderful examples—customized hearing aids, 3-D printed electronics and even shoes as well as [efforts to print artificial human] organs. The government will ultimately decide whether the technology should be regulated, but I see these technologies completely disrupting the way we make products, and bringing innovative, entrepreneurial manufacturing work back to the U.S. We’ve traveled too far down the road to turn back at this point. With these technologies, the future is limited only by one’s imagination.