1. I know metal printers are a thing, any news on them becoming more affordable/viable? I really don’t trust plastic to handle gun parts

   1. Many of these are tested and do work with low pressure rounds. In other cases they used metal for the pressure containing parts.

      For me it was interesting to see a 3d printable AR15 lower. Reportedly this lower had been printed in ABS and was still working fine after more than 2000 rounds.

      That means a rifle part kit plus this printed lower gives you a functional AR.

      The only problem with the link is that you must register to view details and it looks like you have to sign up for another service for a year before you can download files. I did verify that the names of the upload owners are reputable.

   2. There are at least 4 different metal 3d printing processes. Markforged has a downloadable PDF document that discusses them briefly. An interesting one is their creation. It vaguely resembles the plastic “melt a fish line” technique, but the filament is a combination of metal powder and a plastic soluble binder. That is laid down with a thermal filament melting printer. Then the model is washed to dissolve much of the plastic, then sintered in an oven to make a solid metal part. I don’t know the price of those machines; most likely still well above hobbyists numbers but apparently well below older metal printing technologies like powder laser fusion systems, and safer too. It handles metals that are hard or impossible with other processes, like pure copper.
      Another process, also from Markforged and possibly within reach of at least some hobbyists is their plastic and filament system, which is what they started with. It combines nylon with fiberglass, kevlar, or carbon fiber, so you get a composite plastic part with basically the same properties as traditional composites. I’ve been wondering if a 3d printed plastic/kevlar composite receiver would work.

2. I found an article explaining why DefCad is requiring a subscription in order to down load files. Not sure about the $50/year price tag but…

   Under US law, certain things can be restricted from export via International Traffic in Arms Regulations (ITAR). 20 years ago the big thing was that encryption was considered an “arm” and restricted under ITAR. Thus you could not export PGP code from the US. You couldn’t put it up on a computer for download, in the US. Because the bad guys might get an ARM.

   The work around was that they printed the entire PGP code in an OCR font and then took that out of the country, read it in some other country and from then on, all PGP development happened in that other country and we could import the results back into the US. Same thing happened with SSL. Browsers outside of the US could only use “weak” encryption.

   The point of this is that the files that DefCad is sharing are ITAR controlled. This includes blueprints and technical build packages. TBP are the instructions on how to turn a blueprint into something. Order of operations, work holding, tooling, all that good stuff.

   Bottom Line: By using the CC to purchase model and address verification, Cody Wilson can “verify” that the person downloading the files is in face somebody in the US and there by avoid being under the authority of ITAR.

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