Have a look at this (http://members.optushome.com.au/dbsite1/www.pskovinfo.ru/coilgun/index.htm) and tell me what you think. Power seems a little low, but it does look very impressive, being portable.

Cute!
The cap bank is charged to ~180J so if that projectile energy really is 1.5J, then the thing is extremely inefficient.

The thyristor commutation circuit is very elegant and clever. I'll remember that one.

Hmmm though it is inefficient, 33 m/s is the fastest muzzle velocity I have seen for a coil gun, especially one so small.

The fact that it doesn't make a noise, but can pierce tin is also very good, for that means that it would be a good silent kill weapon.

I was considering making a coil gun, but I gave up after I couldn't make it portable enough (I could make things that use electromagnets to acellerate projectiles to high speed, but they were all so big, inefficient and ugly I don't think that I succeeded. I think that I may try again using a plan like this one, although when I finish it I will probably try to make it fire much faster than 25 seconds apart.
I don't know how I can do this yet, so I will need some experimentation, and the site doesn't seem to say the power source.

It says what its powered by...
powered by six AA NiCd accu placed in handle
DC/DC converter charging capacitors to 800V

This seems to be a quite decent gun for its size. Did anyone see anything about the range of this gun? I didnt see anything :confused: I think a rifle would be better though. You could store more capacitors or bigger capacitors in the rifle butt and you would be able to have a larger clip. Does anyone think it possible to have 2 triggers? Maybe one could squeeze one trigger and then the other effectively cutting the delay between shots in half. Just a few thoughts though.

Very cute!
Add on a few more stages (so it's rifle-sized) and it'd be great.

VERY interesting but also scary! The chances to get shot silently are increasing!...Anyway, no doubt we are whitness of the future weapons! And maybe this technology will find some other uses, less dangerous!
How much would cost right now a gun like this ?... :D

anthracis: Isn't the dangerousness of the gun the whole point? :D

Ah yes I just noticed the batteries. That is very good for a gun of that size.

If its muzzle velocity is about 33 m/s, and it has enough force to pierce a tin plate, then I would imagine its range to be about 30+ metres. This is more than enough for a gun of this size, and the fact that it is completely silent is an added bonus.

If a rifle model was made, the butt could hold more powerful capacitors and batteries, for a much faster projectile with more momentum (p = mv). This means it will be better for piercing things.

I did a few tests in comparing tin plates to more real-world targets (i.e. bones) using my compressed CO2 pistol, and found that a small lead projectile which can pierce the tin plate (VERY high pressure required) can smash beef bones, although not pierce through them. But if the subject was shot in the head with a gun like this, just the shattered bones would be enough damage, since they did cave in a little. Unfortunately I don't have pictures because of my digital camera problem :(, but when I get it repaired I will make sure to post some results.

Basically what I found was that the pressure needed (well in a CO2 gun) to pierce tin was enough to cause some serious damage, and aiming for the chest/back would be a great way to kill someone silently (they can't scream with a sucking chest wound)! :D

EDIT
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Assuming the projectile hits no bone (i.e. passes through in between the ribs or between the shoulder blades and other bones) I think it would be quite possible to get a chest wound from a CO2 pistol. The lead balls (not the stupid soft pellets, but the balls) can pierce skin reasonably easily from a range of about 30-50m. Did I say 300? Typo.....30 m :)

Of course, that is assuming that it doesn't hit any bone which is improbable. As far as accuracy is concerned, the CO2 pistols that I have experience with (as well as CO2 rifles) are apparently quoted to be accurate to 80 m. I have only tried them to about 50m, though, and they worked fine at that range. I was probably wrong about the momentum issue, though. I didn't realise that air gun projectiles traveled so much faster! I thought that only gunpowder based firearms provided speeds about 100 m/s. But when I look at it now, 100 m/s is only about 360 km/h. Gunpowder guns have projectiles which travel at over 1000 km/h, which is about 278 m/s.

This information means that the weapon isn't really all that powerful when compared with a proper firearm. It can, though, break thin bone which means it may be good to aim in the temple and other soft areas.

Should have done my calculations properly then.:rolleyes: My mistake.
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33m/s and you expect it to be able to shoot to 300m?? Somehow I don't think so, air pistols with 100m/s aren't accurate to much past 25-30m, and that's from a rest. I'm sure the iron projectiles will retain their energy at much further distances than pellets, but still would not be dangerous.

Chest wound from a CO2 pistol, right... :rolleyes: go back to believing you are some form of aristocracy.

BB firing CO2 pistols are ~1fpe muzzle energy. You'd be lucky to kill and rat with a pointblank headshot with that.

That gauss gun is only pistol sized. If it was redesigned to the size of say an sub machine gun then the size to power would be improved. The gun only has one coil which is why it has a low muzzle velocity.
If the gun was redesigned to have roughly the same dimensions of a FN-P90 which has a barrel length of 263mm and is overall about 500mm long then it would still be quite compact and have much more power. The barrel length of the pistol is ~100mm so you could add one more coil, maybe two. The gun would still have plenty of room for capacitors and batteries. There would be more room for sub-systems so the guns accuracy and reload rate should be improved.

Tuatura; As you probaly know, guass guns are not very efficient. The most efficient guns can may only have an projectile energy of maybe 1-2% of the total energy. If the efficency was able to be improved to maybe 5% then that guass gun would be extremly powerful weapon.
Currently the projectile energy is 0.83% of the total energy output.

My CO2 pistol could probably kill someone, with either a throat shot, or a shot through the eye, and with heavy lead pellets could possibly penitrate all the way to the brain.

My CO2 pistol shoots about 4 pfe, while this gun shoots about 1 pfe. I would really like to see how deep a coil powered rifle could penitrate. Maybe it could be used to take out birds or other small game?

While being an interesting proof-of-concept, this is not yet practical. I do, however, forsee something like this being made much more efficient after superconducting wire at room temperature becomes possible (on a sidenote, I believe there was a nickel-maganese nanotube composition that could do this... saw it a while back in PopSci) When that happens, say goodbye to solid propellant weapons.

Sorry to disillusion you Third_Rail, but superconductivity is not going to result in a perfect gauss pistol. The major inefficiencies result from incomplete transfer of energy from coil to projectile, and the lack of energy recovery circuitry to recycle the unused coil energy back into the main capacitor bank.

As for an energy source, chemical propellants are very hard to beat for energy density, and convenience. This is one of the reasons the airbourne laser weapon research is focused on oxygen-iodine lasers. And one reason why we are not all running electric vehicles.

would it not be possible for to use a torus (ie: donut shape) shaped gauss rifle? i know that some electron excelorators use huge torus shapes to allow the electron to travel a huge distance to gain speed.

of course the iron ball you would use as the projectile would shake the gun quite a bit if it were to go around and around. this could be compensated by with wieght added to the gun (probably in batteries) or a more exotic design would include two guns that accelorate the balls in alternate directions attached to each other.

don't ask me how i would suggest to release the ball in a precise maner. im not even sure how one would release the ball at all. though it would be possible to make the gun only a semi torus or even a coil. either one of those could straingten out into a barrle for a few inches to give improved precisetion.

I had thought the same thing. I can see it being quite an engineering challenge. Not impossible though.
The trick with release would be to have an elongated torus, with a kicker magnet at the start of one of the straight sections to divert the projectile out of the torus.
Vibration would be nasty, and very hard to counter, except with a large gun mass

guys, um, I believe that you are all talking about a rail-gun, seeing as how it uses an electromagnetic pulse to fire the round, but a gauss rifle uses multiple magnets, and transfer bearings, to send energy to the round which then goes on to the target. go to "scitoys.com/scitoys/scitoys/magnets/gauss.html" to read the article on how to build a tiny gauss rifle, with home materials, on the site they also show how to make a rail-gun, out of kitchen materials.

sorry if this reply causes trouble, but the discussion didn't seem to go with the topic title.

I finnished a 4 Joules kinetic output coilgun pistol.
It has two coil stages. The second stage is triggered by a
mechanical contact switch, same as my high power
desktop models. Operation is simple, press the charger
button until the green LED illuminates, load projectile,
then press trigger.

188J capacitor banks:
1. 250v + 250v = 500v @ 750 uF
2. 250v + 250v = 500v @ 750 uF
Projectile: speed = 30m/s, mass = 9grams

The charger is a boost converter power by a 24v NiMH
battery pack. The pack's battery size at present is AA.
Charge time < 5 seconds and consumes 1.5 A thats about
36 Watts. I am currently using a AAA sized pack during
the design of greater power models. Images and videos of
this other other coilguns are at my site.

http://www.anothercoilgunsite.com