Gamers May Get a Charge Out of the Gauss Rifle 98
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."
Re:Rail gun ? (Score:5, Informative)
Re:Power density strikes again... (Score:4, Informative)
But with chemicals you are limited to the amount of powder you can put in a cartridge, while electric guns can have big batteries attached to them. I still don't think portable electric guns are near, but on a stationary platform with lots of electricity (like ships) they could be effective.
Re:My battery is bigger than yours! (Score:5, Informative)
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.
Re:Rail gun ? (Score:5, Informative)
Anything I'm missing ?
Yes.
Coilguns actually are good at shooting conductive pellets, since the induced current creates an opposing field and force. The best pellets are often iron cored with a thick copper sheath, giving the best of both worlds.
Re:Rail gun ? (Score:4, Informative)
Actually the main problem is that to achieve good efficiency the barrel must be very long.
Also you need a fast power supply, which is a major problem for any electromagnetic gun.
Ever see those people with their little RC dragsters? One turn of wire armatures with high current draw cells to power them? I think science has this covered by now, it's only a question of how big a projectile you want to lob. The US Navy has been experimenting with these for years and plan to equip ships with them, capable of lobbing shells well over one hundred miles, at mach 5 or better. Power supplies capable of high current draws and perhaps arrays of capacitors and you're well on your way.