Imgur user NSA_listbot has created the first-ever 3D-printed portable and fully functional railgun that could shoot at speeds for up to 250m/s. All the electronic material like the six wired capacitors and flexible busbars are encased in a 3D-printed housing, and the gun itself is made out of ABS plastic. All electronics are handled by the Arduino Uno R3. The frame is also equipped with an emergency discharge SCR, a power resistor, and a button that could discharge any leftover energy from the caps after they've been fired. The railgun also has pressure regulators in the handle, and its pneumatic system uses CO2 from a paintball tank and directs it to railgun's compressed gas tank located at the handle. According to NSA_listbot, his creation is capable of firing copper-plated tungsten, aluminum, carbon, and even plasma. AutoCAD was used to design his creation.
At 250 m/s or 560 mph, the 3D-printed railgun is no match for the military-grade railgun which could fire for up to 2,200 m/s or 13,000 mph. The performance, however, could be comparable of a standard handgun's - which has the firing speed of 350 m/s. The railgun has six 300J, 350V, 5500uF capacitors that could deliver 3,000 kilojoules of energy per shot. NSA_listbot took his creation to the test and practiced firing graphite and aluminum rods at an aluminum-backed plywood target. The graphite rod seemed to vaporize before impact, while the aluminum rod's impact against the plywood was visibly seen.
Here are the actual recorded tests by NSA_listbot: