Interesting project. Nothing that can't be done without a 3D printer though. Motherjones had an article[0] where the author built his own rifle using a similar method, without the fancy Makerbot.
Also, his point about 3D printers being the 1980s personal computers is off. They're a lot closer to the desktop home paper printers that came out in the 80s. Yes, they let you do something you couldn't do beforehand, but at much higher cost, much lower quality, and much slower than the processes used by industry. Just because I have a laser printer doesn't mean I should print copies of my own book to sell. Flyers for a party? Yes. 3D printers are the same. Print a common household item I'd buy at Walmart? Unlikely. Print a cover for the bottom of my old bike shifter that I can't find online? Yes.
Also, his point about 3D printers being the 1980s personal computers is off. They're a lot closer to the desktop home paper printers that came out in the 80s. Yes, they let you do something you couldn't do beforehand, but at much higher cost, much lower quality, and much slower than the processes used by industry. Just because I have a laser printer doesn't mean I should print copies of my own book to sell. Flyers for a party? Yes. 3D printers are the same. Print a common household item I'd buy at Walmart? Unlikely. Print a cover for the bottom of my old bike shifter that I can't find online? Yes.
[0] http://www.motherjones.com/politics/2013/05/ak-47-semi-autom...