A successor to the Liberator, the SongBird was a single-shot, 9mm pistol that could be printed entirely on a $200 Ender 3 printer. The 2021 files featured a "snap-together" assembly that required no metal springs, using printed plastic "living hinges" instead.
Some of the files available in the DefCAD repository during that time included: defcad files repository 2021
Unlike traditional open-source sites like Thingiverse (which bans firearm files), DEFCAD operates under a strict "access control" model to remain legal within the U.S.. A successor to the Liberator, the SongBird was
expanded its repository beyond firearms, noting an "explosion in popularity" for DIY night vision housings (NVGs) in mid-2021, which could be built for under $1,000 3. Legal and Regulatory Landscape Everytown Lawsuit : On October 22, 2021, Everytown for Gun Safety expanded its repository beyond firearms
released a reinforced AR-15 lower receiver design in 2021, solving previous issues with stock-screw breakage through added plastic reinforcement. DIY Night Vision