HOW TO BUILD A RAILGUN

BRING IT ON, TERMINATORS!

I've been meaning to get to writing this post for some time as it is something near and dear to my heart.. or maybe my brain.  No, it is not some save-the-Earth cause or suggestions on a way to feed the homeless.  This is an article that gives you, the reader, a concise overview of the many ways to build the world's most awesome cutting-edge explosive-free weapon; the rail gun.

For those of you not familiar with this particular form of badassery, A railgun is "an electrically powered electromagnetic projectile launcher based on similar principles to the homopolar motor."  Essentially, in its many forms, it is a pair of parallel conducting rails, along which a sliding projectile is accelerated by the electromagnetic effects of a current that flows down one rail, into the projectile and then back along the other rail.

Railguns first burst into public view in theSchwarzenegger flop; Eraser, but have since become a weapon with a cult following comprised of physicists, engineers and plain old weapons geeks and science buffs.  Even the U.S. Navy has an affinity for this technology.  

For example, in the late 2000s, the U.S. Navy tested a railgun that was able to launch a 7 lb. projectile to hypersonic velocities of approximately 5,400 mph (about Mach 7).  In comparison, the fastest gunpowder-filled bullets travel around 3,300 mph.  Most rounds fired from conventional hunting and assault rifles travel between 1500-2200 mph.

Remember, when you are marveling at the above photo, that all the flames you see are not from an explosion in the normal sense of the word.  In this case it is merely the air crapping its pants and catching on fire. In more scientific terms "The flames are from pieces of the projectile disintegrating; the 7-pound slug is jammed so firmly between the rails that when it’s fired, pieces shear off and ignite in the air."  

But I won't bore you to death with the details.  Ladies and gents, I give you the DIY railgun guide:

**PLEASE BE CAREFUL WHEN ATTEMPTING ANY SCIENCE PROJECT OF THIS NATURE.  WEAR GOGGLES AND PROTECTIVE GEAR AND ALWAYS BE MINDFUL OF WHAT IS DOWNRANGE FROM YOU**

 

Basic explanation of the science behind the railgun.  Gives some interesting ideas as to how to design your launch system and also gives important safety precautions to be taken.

A more in-depth, higher-tech version that shoots a needle-like projectile between two powerful magnets using a daisy chain of disposable camera capacitors.

All the way up to 'Merica-sized.  This is Navy prototype with a test-fire.  Remember, no explosives are used in these guns.  It is all magnets.

Here is a close-up of the projectile leaving the barrel using a high-speed camera.  That fireball is amazing, but is also a reminder to be very careful when experimenting with this technology.  If a projectile can ignite the oxygen in our breathing air like this, imagine what could happen if you had some gasoline fumes lingering around in your garage.

So now that you're familiar, you may be considering toying around with one in your home or garage.  If you're like me and are too curious to let any unknown knowledge go unexplored, here are some blueprints of past successful railgun builders:

Princeton, Physics Dept project

Powerlabs

If you are intimately familiar with how to read electronic schematics, I would recommend the book More Electronic Gadgets for the Evil Genius, Iannini, 2006.  Apart from other cool projects like "Vaccum Coil Tesla Project" and "Ultrasonic Phaser-Pain Field Generator", Chapter 16 "Magnetic High-Impact Cannon"(p 133) may be just what the overachiever in you is looking for. 

I encourage anyone who may attempt to build one of these to post a video on this blog.  It will be very educational for all of us.  Also, while the construction of a railgun is not illegal, full transparency with your neighbors and law enforcement, should the occasion arise, is fully recommended.

Good luck!

Categories: DIY, Science