Coilguns used to be the weapons of science fiction. Nowadays, whenever we see someone build one in their workspace it always serves as an inspiring reminder that the future is now. YouTuber [Cody’sLab] has done just that, assembling a rudimentary — but beefy — coilgun in his workshop.
The one in the video is based off an old design that used a 12V battery and without any fancy electronics. This new model has five coil stages along its two-foot length. Four wooden dowels and two copper tubes are arranged in a hexagonal shape to form the barrel and accelerator rails. The coils are each 100 feet of 14-gauge thin coated copper wire, all connected to a common ground. Still lacking any complex electronics, this version eventually gets its projectile launched a good few dozen feet. The ‘bullet’ is a piece of steel with some brass to prevent it spinning in the barrel, while a hole has been drilled in it to accommodate a spring which keeps the two graphite brushes contacting the copper tubes.
The first test proved to be a little underwhelming, and [Cody] had to try something drastic — so he hooked it up to an arc welder to fire the projectile using 22V and 200A.
http://www.youtube.com/watch?v=Py8BdLTZEAE
We look forward to the next version of an always cool project concept. For a Gauss rifle that looks a little more like its sci-fi heritage, check out this Airsoft rifle with a triple laser sight and infrared scope.
[Thanks for the tip, Thundersqueak!]
V=L*di/dt
yup… inverter welding sources do have something like 50-100V open circuit voltage to get the arc running… should do better…
73
My tombstone welder has an 89v ocv.
Maybe that is tin coated wire? ;-)
From looking at the picture, it is probably THHN coated wire which is a common wire in the US.
This is fucking retarded. I don’t think this counts as a coilgun, or futuristic…You are pandering for web traffic. Use actual content or you will have a mass unfollowing on your hands.
With such insightful comments hopefully you will be among the first.
Yeah, it definitely doesn’t use an electromagnet to fire a propellant-free projectile… OH WAIT. WAIT… that’s right, it fucking does.
I’m confused a Railgun needs the projectile to contact two rails and current is run between the rails to function, a coilgun is a series of coils to accelerate a magnetic projectile by a activating them in sequence to pull the object.
What is this, it has coils and rails that the projectile touches? :)
I think this design is flawed the coil should be ahead of the tube section that activates it by at least half its length, because now the object is accelerated in the first half of each section and decelerated after it passes the midpoint.
The rails the projectile touch are the contacts to switch each coil in t
I’ll try again .
The “rails” are the switch contacts made by the projectile to energise each coil in turn as the projectile moves down the “barrel”
I love Cody’s Lab channel!
I know this is cheating, but has anyone tried to cross a regular projectile weapon with a coil gun? Using gun power to get the initial speed, and getting the timing to add additional speed to it as it goes? I mean one of the things you would want to study is the effect of friction on high speed projectiles as well as the amount of energy you could add to it on the way out anyway. Although not a pure weapon per say, it might be interesting to see if it were possible to do. A hybrid weapon with a really long projection barrel, add a high speed chronometer, maybe high speed photography added in. If you take the standard ballistics of a regular round, what practical energy could you add to it? (I imagine you might actually slow it down with the wrong timing)
Most (serious) coilguns have injection systems: usually equivalent to an airgun.
Good to know, I was unaware. It does make sense as the initial energy for movement would be significant to get it moving.
without the initial energy the projectile will most likely weld to the beginning of the rails in a ‘rail gun’.
a hybrid could be the best of both worlds
i would love to optimize this design.
add more or less sections
individual rail pieces and cap bank instead of common ground/supply
make the rails more rail-like
place the coils in a proper position for coilgun-like operation
find the perfect balance of rail vs. coil current / impedance matching…hint hint
find the perfect balance of linear and polarized magnetic fields
Though I’d like to point out that “a few dozen feet” is all the performance people got out of them when they were still regarded as science fiction :-p
Maybe one could get more distance by holding the projectile in one’s hand and applying shocking voltages to the arm muscles.
Instead of the copper tubes why not an optical sensor at the start of each coil. Also maybe a magnet in the projectile.
Based on past history of the internet, I probably should not bother, but here goes:
The projectile should be nonferrous and work by repelling the projectile.