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Gamers May Get a Charge Out of the Gauss Rifle
Zothecula writes "Well, Patrick Priebe might have outdone himself with this one. In the past, the German cyberpunk weapons-maker has brought us such creations as a wrist-mounted mini-crossbow, a laser-sighted rotary-saw-blade-shooting crossbow, and a flame-throwing glove. His latest nasty futuristic device? A video game-inspired electromagnetic weapon, called the Gauss Rifle."
From the description is'nt it more of a railgun type of weapon ?
are we talking starcraft gauss rifle? fallout 3/new vegas gauss rifle? it looks like it belongs in dead space. it also looks like a glorified version of this http://www.youtube.com/watch?v=QPciBQnZw3c
insensitive clod overlords obligatory xkcd car analogy russian reversals whoosh pedant fanbois ftfy in 3...2...1..PROFIT
This was in SF books, in the 70's.
As for gaming antecedents, do you remember the role-playing system, Traveller?
When I was a teen - around '79, I remember Gauss Rifles, and polyhera dice in the game. This was when the video-game combat state-of-the-art was Asteroids and Space Invaders...
"Flyin' in just a sweet place,
Never been known to fail..."
As with electric cars and aircraft, the power density of boring, smelly chemical fuels are just stubbornly competitive with electric tricks...
It's a pity, because they are much more entertaining; but it's persistently the case.
I love the smell of toasted zergling in the morning.
TFA: Fortunately, he has no plans on developing it commercially, or on telling other people how to make one of their own.
Capacitors, em coils, pressure sensors... you pretty much already told us how to build it. Of course, anyone with an IQ above room temperature could have worked that out from the descriptions in the various games that employ similar weapons. I personally would have gone with something other than pressure sensors to trigger the next coil -- wear/tear, added drag, etc. -- but to each his own.
As far as producing it commercially? The US Navy is already working on that, thanks.
This guy has a history of making cool garage-project, working replicas, but it's nothing as innovative as all that. There's a reason soldiers are still carrying around powder-charged ammo instead of giant power packs and several pounds of coil.
You have your engineering constraints wrong.
The battery size reflects the "clip" size. You'll be lucky if your battery size/weight is much smaller than the ammo it flings for a bunch of basic chemistry reasons. A battery the size of a truck trailer would be able to fling a volume/weight of ammo about the size of a truck trailer, either all at once or more likely eventually. In other words the energy density of chemical batteries is never going to be a whole heck of a lot better (like orders of magnitude, not the smallest decimal point) than the energy density of smokeless powder. Hence the intense interest in hypersonic projectiles. I suppose if you had a nuclear aircraft carrier or nuclear powered submarine to power it, then ...
The velocity reflects the weight and number of the coils. Something that is pretty wimpy compared to a slingshot is about the most a human can handle. If you insist on hypersonic velocities its going to be immensely huge and probably quite inefficient as a tradeoff making the whole weapon system fairly useless.
Your budget reflects the total projectile energy via capacitor bank size. Something light enough you can pick up and an individual might be able to afford makes for the worlds wimpiest pellet gun, not much more than airsoft really. If you insist on blowing up a tank, you'll need a truck trailer full of capacitors costing about as much as a house. Capacitors are a really awful way to store energy, but the only way to release the energy quick enough for hypersonic power. If you get serious, internal resistance and crushing magnetic forces and strange resonant effects become a big problem (no longer able to treat the cap as the simple AC/DC electronics 101 simplification of a perfect device anymore)
Usually the limiter for the home builder is triggering followed by power supplies. Whats most likely to stop you is finding a big and bad enough set of SCRs or whatever to handle triggering or if you try mechanical like this guy you end up accidentally building a arc welder, second your average noob is mystified at how to generate more than a couple hundred volts without spending lots of money or getting killed or blowing up the trigger system. If they succeed at that, the next limiter is usually the spectacular cost of high voltage low resistance high capacity capacitors... any 1 or 2 of the 3 isn't going to do, and maxing out all 3 is going to be very expensive. Assuming you pull that off, coils are pretty simple, as are batteries.
"Science flies us to the moon. Religion flies us into buildings." - Victor Stenger
Skul-gun?
If God forks the Universe every time you roll a die, he'd better have a damned good memory.
For even more 'awesome but impractical' bonus points, I suspect you could modify this so that the laser sight actually shines out of the barrel. Repurpose the mirror-flipping mechanism out of an old SLR camera.
Quattuor res in hoc mundo sanctae sunt: libri, liberi, libertas et liberalitas.
It looks neat, but performance is unimpressive. 328 FPS is only about a third of the muzzle velocity of 45 ACP pistol ammo
I agree.
A reply to that comment
what is the weight of the projectile
it is slow, but if it is 3 X heavier than a 45 ACP than it would deliver the same power to the target
If it is 3X the mass and travels 1/3rd the speed, it carries 1/3rd the energy.
Won't somebody please teach the children science?
I want to see a Quake 1 lightning gun.
God spoke to me
So, I guess conceal/carry is out of the question.
You are welcome on my lawn.
What do you mean, overcharge?
With 3X the mass and 1/3rd the speed it would have the same momentum. Granted, the power, as in energy, delivered would be less, but with a weapon you might be more concerned about momemtum. A small high-energy particle might pass completely through a target while doing minimal damage. But a larger particle with less energy might be able to do more damage, or at least have a greater chance of knocking the target down, often referred to as "stopping power". Consider a gun battle between two beligerents, and suppose one of the combatants shoots the other with a smaller bullet that passes quickly through their shoulder. Imagine that the impact slightly jolts the combatant, but they quickly recover their position and aim to hit the other combatant with a much larger bullet that might be moving much slower. The larger bullet may impact the combatant's shoulder in a manner identical to the first, but the impact from the larger bullet might have the affect of knocking the combatant off balance, perhaps to the floor. Penetration might not even be lethal depending on various factors, but being knocked off balance, on the ground, the second combatant is at much of a disadvantage if the first pursues the second for follow-up shots that keep him down and possibly end in fatality, such as a shot to the head, which is fatal even with a rubber slug.
A bit of research tells me that 45 ACP rounds are about 10-15 grams. The video says the railgun projectiles are 5.6 x 16 mm.. I'm assuming both are mm, then, which would mean a perfect cylinder would have 0.394 cm cubed of mass. Most steel seems to be about 7.5 gram per cm3, so that'd be about 3 grams.. a little less, because it's not a cylinder.
It has 1/5th the mass, and 1/3rd the velocity. Kinetic energy would be.. what. 1/75th?
These numbers seem excessive, so please correct me if I'm wrong. It's rather shocking that a pretty well designed, heavy coilgun only gives 1/75th the power of an average handgun. Especially since said handgun can probably unload its ammo into its target 5 times faster.
Everything you said is true. But don't get the idea that smaller, high-velocity bullets are useless - otherwise, we'd still be using 20mm musket balls. Bullets since the Minie ball in the American Civil War have been designed to offset their lack of stopping power with fragmentation and wounding effects - your hit through the shoulder isn't just going to zip in and out. It's going to zip in, shatter, then tear out, taking many times its volume in flesh with it. And the smaller, lighter ammo and easier recoil are also demonstrable benefits.
Everything is better with chainsaws.
Had this guy released the plans I might not have looked at them, but since he offensively censored the information I went and learned all about coil guns.
"When information is power, privacy is freedom" - Jah-Wren Ryel
I just knew that living beside high voltage transmission lines would come in handy someday!
The tyrant will always find a pretext for his tyranny - Aesop
It's not excessive. The energy stored and released by the capacitors in this guys rail gun is nowhere near as much as the amount released by the gun powder in a bullet. Assuming those are 100uf 400V capacitors, you're talking about 1600J, a fair amount of that would be lost as heat in the internal resistance of the capacitor and the resistance of the coils. The projectile carries around 10 - 15J of energy.
In all honestly, the "coil gun" concept really doesn't make a whole lot of sense. Electromagnetic coils can't be instantaneously turned on and off. The magnetic reluctance of your coil means it takes some amount of time for the field to come up to strength as power is applied, and some amount of time for the field to dissipate after power is removed. Even if you had tons of stages, and those stages were perfectly timed, the reluctance means that at the switching speeds you need to operate at, you're getting terrible efficiency. It's common for only a couple percent of the consumed electric energy to be converted to kinetic energy in the projectile. Coil guns are fine for large scale linear motors, but the scaling parameters don't work well for something handheld.
If you want a weapon, you want a railgun. Compared to a coil gun, it's dead simple. Make two rails. Put a conductive projectile at one end. Apply low voltage and ludicrous levels of current through the two rails. There's nothing really to control, you just dump everything you can, as fast as you possibly can, into those rails. With proper low resistance materials, energy transfer efficiency can reach into the several tens of percent range. The problem is that just as the projectile is being pushed along the rails, the rails are being pushed apart. As the rails flex away from the projectile, plasma arcing destroys the rails, so the real trouble is finding materials that can withstand the damage repeatedly, so you don't have to re-machine the barrel every couple shots.
That's why modern rifle rounds are unstable, but spin stabilized. Low weight and high velocity means they have good range and accuracy, as well as some ability to penetrate armor. Instability means when they are disrupted by some kind of resistance, like a human, they tend to yaw violently and then fragment. Technology to provide all the lethality of a hollow point bullet, but without violating the Geneva Convention.
These numbers seem excessive, so please correct me if I'm wrong. It's rather shocking that a pretty well designed, heavy coilgun only gives 1/75th the power of an average handgun.
Coilguns only do a few percent efficiency. Out of a claimed 500J propellent energy from the caps, only some 15J or so were transferred to the projectile.
Accidently squared the 1/5. Derp. Still a tiny number though.
Wonderful! And is it attached to a battery pack the size of a truck trailer?
So, I guess conceal/carry is out of the question.
Except on the road, if you make an 18 wheeler your daily driver.
"You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
I just took one look at the picture and thought the guy made it with 8 iPads. I felt a sigh of relief to know that no one would've been that stupid, but also paradoxically felt bummed that they weren't.