I did some work on the AR10 model, increasing the surface area in contact with the printbed, so it will adhere better to prevent warp.
Here it is with all the parts installed. The rear takedown pin fractured the case when i pushed it through. Those are really tight, and next time I’ll have to make the opening just a little bit bigger.

My AR10 magazine came today, and as i suspected, the warp on the front of the case made the magazine fit poorly. It fractured the case also upon insertion.

Here you can see the lower from the other side. It looks fairly complete. All i need is a buffer tube and complete upper and I’m good to go!

This is a good example of the increased surface area I added to the model. In the original lower, that flat area would have a rounded profile.

Here you can see the surface area I added to the front section. In V3 I added more surface area to the lower edge of the magazine well, and hopefully that will stop the warp which can just be seen in the lower edge of this picture.
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Kudos to you, sir, for having the
reckless abandoncourage to actually fire with a printed lower receiver.Thanks! I look forward to a post of your
shoulder injuryfirst successful .308 test! :-) Hopefully more people will be encouraged to push the limits of 3D printing after seeing projects like this.How would you “print” a gun using Direct Metal Laser Sintering ? Where can I find / buy computer files to do so ? Thingiverse seems to focus mainly on hot plastic deposition using a MakerBot or something similar. Is there a site for Direct Metal Laser Sintering enthusiasts ? I’d feel a lot more comfortable with a reliable metal or carbide assembly instead of a plastic gun which will melt at the wrong moment.
Short answer: same way you would print an object in plastic. And the files are all over the net. i got mine from justin at CNCGUNSMITHING. Haveblue’s lower on thingiverse is also attributed to justin.
I don’t use a metal printer, but it would be silly for them to use different types of files than the ones for printing in plastic.
Thingiverse has files for printing in plastic because thingiverse is run by makerbot, a company that makes a plastic printer. Plastic printers are what most hobbyists can afford. The metal printers available now run into the tens of thousands of dollars for just the machine, and the finely-ground powder needed to manufacture with them is also very expensive.
There shouldn’t need to be a different wobsite for metal printers, because all the files are just 3-d models. Any kind of 3-d model could be printed. STL is the most common kind of 3d model used in printing, because they represent an object in 3 dimensional space using a series of triangles.
an ABS printed lower receiver is in no danger of melting. There have been plastic lowers for decades, and none of them have melted. They just aren’t exposed to the heat.
It is clear from your questions that there is a wealth of information on the subject of armsmithing and 3-d printing that would aid you in understanding the answers i have provided.
I suggest the following sites.
AR15.com
Reprapwiki