Record Of The First Failure Of A 3-D Printed AR Lower Receiver

Remember the project that is trying to 3-D print an AR-15 lower? They have a website. They successfully printed one. Then they took it out and shot it until it failed. After the sixth round the butt stock and the recoil tube broke off, incapacitating the rifle.

Sounds like that part needs more work.

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4 Responses to Record Of The First Failure Of A 3-D Printed AR Lower Receiver

  1. BrunDawg says:

    The ink was too brittle.

  2. BigJimTX says:

    We were looking into prototyping some parts and we came across a compound that was 3D printable, but had the material properties of aluminum. I don’t remember where we found it, but I’ve been unable to locate it again.

    Realistically, you are better off buying a mill and a couple of 0% receivers. 3D printers can run upwards of $50k.

  3. notamobster says:

    You can get a decent home 3D printer for 5K. You can print in many different materials (from chocolate to solder/tin/plastic).

    I can tell from the discoloration on that break that they used the wrong plastic. It was far too brittle. They should use a more impact-resistant HDPE – as opposed to what looks to be a brittle polypro.

  4. Greg B says:

    There are some small home table top printers that can be either built, or bought outright for less than a couple grand. But they really are just playthings. One of my friends has one, and while it is neat, the only real use it has is making things from plastic, that would have been made from plastic in the first place. But it is NOT efficient.
    3D printers mainly were developed for rapid prototyping. And that is the key word here.
    Even the high end industrial printers can’t match injection molding for mass production. And although there are some polymers that are incredible materials, I imagine it will be a long, long time before something called plasteel is viable. (Stole that term from a SF book)
    The guy who I read about make a printed AR lower used it for a .22 pistol platform. Much less stress than a high powered rifle.
    And look at the time involved in making the receiver in the video. Seven hours? And the next one will take that long too. I could spend that time programming the code, with high end CAD/CAM software. And incidentally, there are some open source CAD/CAM packages out there for free, that are very powerful. Then machine one in probably half the time. That’s including secondary operations.