Someone Stole My Idea For An Electrical Coil Gun!!!....With Video

[twyacht]

I knew another "sparky" would come along first,....

http://thetruthaboutguns.com/2011/08/foghorn/nifty-hack-turns-airsoft-guns-into-coilguns/#more-61543



Airsoft is fun (I guess, I’ve never owned any Airsoft guns), but what about when you get bored of shooting little plastic gubbins and yearn for steel instead? Hackaday, the blog that constantly amazes me with the ingenuity of a bored human mind, has a suggestion: turn your air-powered pellet chucker into a supercharged steel-slinging coilgun. I saw this posted earlier and it was just way too awesome not to share with all of you. Make the jump for a quick explanation of what a coilgun is and some video of the gizmo in action.

A coilgun uses magnetism to accelerate a projectile down a barrel. The magnetic force is created using a coil of copper wire attached to a capacitor. When the capacitor is tripped (the electricity stored within transmitted through the coil) the electricity flowing through the wire creates an instantaneous magnetic field that acts on the projectile and moves it forward. By the time the projectile gets to the coil the energy in the capacitor is spent, meaning that the magnetic field disappears and doesn’t keep the projectile from continuing on its path. Multiple coils can be used in series to increase the velocity of the projectile. This is different from a railgun, which introduces electric current to the projectile itself instead of a coil.

Because the force acting upon the projectile is magnetism and not a chemical reaction (like gunpowder) this is technically not a firearm. However, quick witted ATF boffins may note that a chemical reaction in the battery is the actual primum movens in the mechanism. In other words, I sure hope the ATF doesn’t get wind of this and start classifying batteries as ammunition.

1.5v,.....sheesh do you know what the muzzle velocity would be with a 9volt?  How about a 12volt jetski battery in a fanny pack with a quick charge toggle connection to the capacitor?

At least he added a blocking diode in the firing sequence, wouldn't want a backfeed,.....aka kaboom,....

Maybe, a larger coil? Methinks I have to go back to the shop and try a carbine version..... Where's FQ, to test on toads?

[fightingquaker13]

You're the electrical guru TW, build one. As far as toads, I offed one today. The cheeky bugger was staring right at me through the kitchen window. Error! Never let it be said that I won't tolerate a .22 hole in the screen for the greater good.
Methinks though that you will have no shortage of toads and iguanas to test it on.
FQ13
 

[alfsauve]

Not very high velocities with this arrangement.   Better would be successive coils with a timer that fires each one in turn further accelerating the projectile.  Projectile of necessity must be ferrous and probably can't use rifling.   Also, the coil, being and inductor, itself, cannot really generate a real sharp edge wave form as the nature of an inductor (coil) is to resist sudden current changes.

A more powerful solution is a rail gun.    Still uses an inductor but the inductor is only 2 straight rails.  They have a very low resistance to sudden surges of electricity.  The bullet is any metal, not just ferrous.

The navy has demonstrated a rail gun launching a 7lb projectile at 5,400 MILES/Hour.  That's about 51,000gr bullet at 7,920fps with a power factor of 408,000.    We're talking MACH 7+ at sea level.

Problem is they haven't made these too small yet.  Still "shipboard" size.   And the current necessary for one shot, could light a major city.  Think 100,000 to a million Amperes.   Also the heat generated tends to shorten the life of the rails.

Oh, invented in 1917 by a French inventor and patented in 1920 in the US.  Also known as a linear motor.

[ellis4538]

My thoughts exactly alf.....huh, what?

Richard

[twyacht]

Not very high velocities with this arrangement.   Better would be successive coils with a timer that fires each one in turn further accelerating the projectile.  


Good food for thought alf... By the drawing he is generating/utilizing 100,000 k ohms of resistance, using a 1.5v to 300v capacitor. As it generates a instant magnetic field of opposing poles,...one could beef up the ohms, easily beef up the capacitor and power supply, I think rifling could work...

I'll have to think about current, but it should be low, I just need voltage sent to charge the capacitor, resistance generated and held until the trigger is pulled. We short out stored voltage in capacitors for testing AC units and Freq. drives on ventilation systems quite a bit at work.

An inductive load is generally low current (hence the diode only .7 voltage drop), I think the resistive current on the input can be easily managed safely, if I boost the power, ie 9v....Lithium-ion comes to mind, with rechargeable batteries... Like a cordless drill...
or cell-phone....

I'll kick it more around with some "co-workers in low places"......

Nothing like the potential for a good Blaster....

Great,....now were on ANOTHER LIST>>>>.

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