DIY Barrel Rifling with 3D Printed Help

[Jeff Rodriguez] has been busy testing a feasible DIY method for rifling a barrel and has found some success using salt water, a power supply, wire, and 3D printed parts to create the grooves of rifling without the need for any moving parts or cutting tools. Salt water flows between the barrel’s inside surface and a 3D-printed piece that holds wires in a precise pattern. A current flows between the barrel and the wires (which do not actually touch the inside of the barrel) and material is eroded away as a result. 10-15 minutes later there are some promising looking grooves in the test piece thanks to his DIY process.

Rifled barrels have been common since at least the 19th century (although it was certainly an intensive process) and it still remains a job best left to industrial settings; anyone who needs a barrel today normally just purchases a rifled barrel blank from a manufacturer. No one makes their own unless they want to for some reason, but that’s exactly where [Jeff] is coming from. The process looks messy, but [Jeff] has had a lot of space to experiment with a variety of different methods to get different results.

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Watch The Diesel Effect in Ballistic Gelatin

A striking video appears to demonstrate an explosion via the diesel effect in clear ballistic gel. The diesel effect or “dieseling” refers to when a substance ignites from the effects of pressure, and it’s the operating principle behind the gadgets known as Fire Sticks or Fire Pistons.

diesel-effect-ballistics-gelBallistic gel is a broad term referring to a large chunk of dense gel generally used in firearms-related testing to reliably and consistently measure things like bullet deformation, fragmentation, and impact. It’s tough, elastic, and in many ways resembles a gigantic gummi bear. Fans of Mythbusters (or certain DIY railguns) will recognize the stuff. Water-based blocks made with natural gelatin can be easily made at home, but end up with a yellow-brown color and have a limited shelf life due to evaporation. Clear blocks exist that are oil-based and don’t dry out like the water-based ones. It’s one of these that is in the embedded animation below.

Slow motion video capture is a natural companion to just about anything that you’d need ballistic gel for, and good thing — because the video captured what appears to be a diesel effect! The block is hit with a bullet, and as the bullet rapidly expands and dumps its energy into the gel, a cavity expands rapidly. During this process, some of the (oil-based) material in the cavity has been vaporized. After the expanded bullet exits (to the right of the gif above but easier to see in the video below), the cavity in the block begins to collapse. The resulting pressure increase appears to ignite the vaporized material, which explodes with a flash followed by some exhaust.

This effect has been observed in ballistic gel before, but this video shows a particularly clear ignition, followed by a secondary expansion of the cavity, then a flatulent-ish ejection of exhaust as the cavity collapses. If nothing else, it’s a very striking effect clearly captured on film. Slow-motion capture of destructive forces makes visible many things that would otherwise happen too quickly to perceive.

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The first 3d printed gun has been fired, and I don’t care.

3d-printed-gunSeveral people have sent us this story. I’ve seen it everywhere. A lot of people are upset, on several sides.  A gun has been 3d printed that can actually fire a round.

First, we have people scared that this will bring undetectable guns to people who wouldn’t have had access before. Then we have the gun fans that are reacting to the others with shouts of freedom and liberty and stuff.  The 3d printing community has had mixed reactions, but many are concerned that this will harm 3d printing in general.

I simply don’t care.

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