Hard Light Productions Forums
Off-Topic Discussion => General Discussion => Topic started by: jr2 on September 08, 2007, 02:31:16 am
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http://www.gausspistol.com/
Whatcha think?
(http://www.gausspistol.com/sitebuilder/images/Dscn2963s-659x548.jpg)
(http://www.gausspistol.com/sitebuilder/images/Dscn2937s-311x222.jpg)
--More photos (http://www.gausspistol.com/photos.html)
--Videos (http://www.gausspistol.com/video.html)
A Real Electromagnetic Pistol!
* Three coils are precisely pulsed in
sequence to fire a steel projectile
* Two infrared sensors detect the
projectile position within the firing
tube
* Controlled by a PIC microcontroller
* Powered by 8 AA NiCd battery pack
* Built-in battery charger
* Bar display tracks capacitor bank
charge progress
* Battery and Fault LED indicators
* Laser targeting sight
* Makes no sound when fired
How It Works:
The GP-219 Gauss Pistol is a self-contained, two-stage coil gun. What follows is a brief
description of each subsystem and how it all works together to accelerate the projectile.
(http://www.gausspistol.com/sitebuilder/images/blockdiagram3-679x485.jpg)
Subsystems
A. 8 x AA NiCd Rechargeable Battery Pack
Nominal voltage +9.6 VDC
B. DC/DC Converter Unit
Battery charging circuit
Capacitor Bank charging circuit
Regulated +5 VDC output
Regulated +20 VDC output
Laser module supply
Temperature sensor
C. Energy Storage Unit
Capacitor Bank 1, 1,620 uF, 450 VDC
Capacitor Bank 2, 540 uF, 450 VDC
Two parallel-IGBT circuits, one pair to fire each coil
D. Control Unit
PIC microcontroller manages all pistol functions (description below)
Ten-segment LED bar shows cap bank charging progress
"Ready", "Battery", and "Fault" LEDs
E. Sensor Unit
Two infrared reflection sensors detect presence of the projectile
F, G. Coils
Two hardened solenoidal coils, surrounded by iron to enhance flux linkage
H. Preaccelerator
Projectile is held in place magnetically (so it doesn't fall out prior to firing).
Initial velociy (<2 m/s) achieved using a solenoid fired by 10V Ultra Capacitors, which injects
the projectile into the firing tube.
Microcontroller I/O (PIC16LF819 (http://ww1.microchip.com/downloads/en/DeviceDoc/39598e.pdf))
Analog Inputs
Temperature level
Battery voltage level
Capacitor bank voltage level
External (battery charging supply) voltage level
Digital Inputs
Projectile detection sensor 1 (interrupt)
Projectile detection sensor 2
Digital Outputs
Fire control 1
Fire control 2
Cap bank charge control
Battery charge control
"Ready" LED indicator
"Battery" LED indicator
"Fault" LED indicator
The Firing Sequence
1. When the trigger is pulled the Preaccelerator injects the steel projectile into the firing tube.
(A non-ferromagnetic projectile will not work).
2. Optical Sensor 1 detects the presence of the projectile at the entrance of Coil 1, and
triggers an interrupt inside the micro.
3. The micro waits for a specified delay time after receiving the interrupt before pulsing the
IGBTs, dumping the charge stored in Capacitor Bank 1 through Coil 1.
4. The resulting magnetic field sucks the projectile into Coil 1. The pulse time is precisely
controlled by the micro to ensure the field collapses fully by the time the projectile is midway
through Coil 1.
The pulse turn-off is the most critical aspect of timing. If any of the magnetic field is still
present after the middle of the projectile passes the midpoint of the coil then the
projectile will experience a "suck-back" effect. Late turn-off could not only slow down the
projectile, it could even cause it to change direction and shoot backwards!
5. The projectile is detected by Optical Sensor 2 when it emerges from Coil 1.
6. The micro waits a specified delay time before pulsing the IGBTs, dumping the charge
stored in Capacitor Bank 2 through Coil 2.
7. The resulting magnetic field accelerates the projectile into Coil 2. The pulse time is
precisely controlled by the micro to avoid the suck-back effect.
All delay and pulse times are calibrated by trial and error to optimize muzzle velocity. These
constants may be reprogrammed for nonstandard coil or projectile specs.
Charging the Capacitor Banks
Charging the Batteries
I will be adding to this page in the near future, including empirical results!
Frequently Asked Questions:
What is a Gauss Pistol?
A Gauss Pistol is a specific kind of "Coil Gun". The term "Gauss" is a unit of magnetic field
strength (the magnetic field of the earth is around 1 Gauss), named for the great German
mathematician Karl Friedrich Gauss (http://en.wikipedia.org/wiki/Carl_Friedrich_Gauss). "Pistol" refers to a gun that can be held and fired with
one hand.
Gauss pistols, gauss rifles and gauss cannons feature prominently in many sci-fi books, video
games and role playing games as stock "weapons of the future".
Then what is a "Coil Gun" ?
From HVWiki (http://wiki.4hv.org/index.php/Coil_gun): "Coil Gun: A device that accelerates a ferromagnetic projectile using a coil of
wire and a pulsed power source, usually capacitors. A large current is put through the coil,
making it magnetic and attracting the ferromagnetic projectile. When the projectile passes
through the coil, the current switches off and the coil loses its magnetism, allowing the
projectile to keep going".
Many Coil Guns take advantage of a multistage design, which involves winding a series of
individual coils along the barrel, each of which is fired in sequence adding some (diminishing
amount of) velocity to the projectile. My pistol design has three coil stages.
Isn't that the same as a "rail gun"?
No. A rail gun operates on a different principle than a coil gun, check out this great explainer (http://www.railgun.org/)
for more details on rail guns.
Why would anyone want to build one?
This project brings a wide variety of engineering disciplines together: assembly programming,
DCDC converter design, thermal management, mechanical design, battery charging, high
current switching, and electromagnetic fields. The gauss pistol project has been a great
challenge and extremely rewarding!
I could use one of these for home security, right!?
This product is for educational purposes only. It is NOT a weapon! You would be better
off buying a nice slingshot (http://www.archeryexchange.com/products/novelty/slingshots/sst-122.shtml) for home defense.
How is a Gauss Pistol better than a regular gunpowder type pistol?
It isn't. Firearms are in no danger of being supplanted by coil guns anytime soon. Coil guns
weigh more, cost more, are far more complex and far less reliable than ordinary firearms. The
limitations of modern batteries are one major obstacle.
So what good are they? There is an inherent speed limit on the muzzle velocity in an
expanding gas powered gun (such as a firearm, cannon). This is due to the high
temperatures and pressures created in the explosion, which effectively places a speed limit of
around 2km/s for this type of system (earth's escape velocity is >11 km/s, for reference).
It is theoretically possible to achieve much higher velocities than that with a coil gun, (maybe
one day approaching a significant fraction of the speed of light!) since there is no explosion
involved. NASA is working on putting payloads into space (http://www.fas.org/news/iraq/1998/05/980500-bull.htm) using big coil guns.
What education do you need to be able to design something like this?
I have a BS in Electrical Engineering and a BS in Computer Engineering. Nothing has pleased
me more than all the responses from younger visitors who say this project has sparked an
interest in electronics!
Would it improve your gun if you used supercunducting [sic] transporters and 1000V
fuel cells to get more voltage through the ciols [sic]?
Huh?
Why aren't you using Lithium-ion batteries?
Now that's a good question. Lithium-ions have much better energy density than either NiCd
(at least double) or NiMH (a bit less than double). The unfortunate downside is the Peak Load
Current is about one-tenth what a NiCd can safely supply. This is insufficient for the capacitor
bank charging rate I wanted.
Lithium-polymer batteries are available that have high energy density AND high peak load
current, but that would put me way over my battery budget for this project.
Is your Gauss Pistol dangerous?
Yes, in fact the GP-219 is potentially dangerous in many ways:
* Fully charged, the capacitor terminals have 450V across them. If you poke your finger
around in there you could really get a nasty shock.
* The pistol weighs almost 3 1/2 lbs, so it would be dangerous if hurled it at someone's
head or face.
* The sight is a Class IIIA laser module, which causes retinal damage if stared into for too
long.
* When disassembled, many of the plastic parts could pose a choking hazard to children
under 4.
* The kinetic energy of the projectile as it leaves the barrel is a little more than a CO2
pellet pistol. Though the energy is similar, the Gauss Pistol projectile weighs around
12.5 times more than a lead pellet and travels about 30% as fast. It could definitely
cause bodily injury. Never point any weapon, whether turned off or unloaded, at anyone.
Only you are responsible for your actions.
Are you dangerous?
Only when cornered. Or spooked.
Don't you think you have ANY ethical responsibility for selling deadly weapons
intended to kill people?
I have a personal interest in getting as many people as possible interested in learning about
electronics and physics, and hopefully influence a few into making it a rewarding hobby or
career.
There are many high-voltage kits available, tesla coils (http://www.amazing1.com/tesla.htm), "jacobs ladder" (http://www.amazing1.com/jacobs-ladder.htm) etc, which could be used
in a violent manner against innocent people or pets. Since they do not happen to be gun-
shaped (http://en.wikipedia.org/wiki/Hoplophobia), no one seems to get worked up about these items.
Can I buy one?
First I have to make sure I'm covered liability-wise. If you think you might be interested then
feel free to contact me (http://www.gausspistol.com/contactus.html) and let me know.
How much will they cost?
The full assembly book w/ CD-ROM disc will be $20 - $25 USD, full kit of all parts with the
book will be < $400 depending on my final costs.
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huh?
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Did you click the link? Or don't you understand the link? :p It's an electric pistol. Read the link. :nod:
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(http://www.nukelol.com/lolwut/1188197924507.jpg)
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Electromagnetic pop/'air' gun...
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"Why would you bother building a gun that's less effective and more expensive than a regular, mechanical gun?"
"Because it's cooool"
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"Why would you bother building a gun that's less effective and more expensive than a regular, mechanical gun?"
"Because it's cooool"
:nod:
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Soo...is this for killing people or what...
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doubt it could kill a bird tbh
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[crazy conspiracy mode ON]
USA has coilguns and railgunz I tell you! All their starships in orbit of Pluto are equipped with them.
Hell, they even launched ppl on hte Moon with a massive coligun..that rocket was a FAKE! To fool the aliens that we are no threat to them! but the US is planing to invade Mars! Interplanetary war I tell you!
[crazy conspiracy mode OFF]
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invade mars eh....
think its a good time to get you a white jacket and a soft walled room now
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Sure it can be lethal... If you swing it hard enough...
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The US has had experimental rail guns for a while now, and they are starting to reach a lethal capacity ...but I'd say its at least a good twenty years or more before you see one deployed. We are advancing alot of electricity storage and control related tech for cars and the like, which might snowball these things from being toys into being a relatively dangerous weapons rather quickly.
From a 2nd amendment / citizen weapon standpoint, this makes the debate as interesting as the Tazer has in recent years.
Firearms are heavily regulated (altho poorly controlled) in most nations, where air guns almost ignored.
The Tazer started out as a joke but has slowly found itself the target of growing regulation as people are beginning to realize its an effective weapon.
I'm wondering if a working electric pistol falls under the line of air guns (minus the air of course) or if they will be lumped in with electronic weapons like tazers.
If it goes the road of regulation then how will they attempt to control this?
Its all off the shelf parts if you have the know how.
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Ya, well, in NY, they regulate crossbows and throwing knives, too... not that it helps much. Do they wish to regulate steak knives? What about when someone puts together their own crossbow? I think all you need is heavy consequences for using weapons in crimes.
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"Look mate, it's just a plutonium core and some explosive. I wasn't going to commit a crime with it so why shouldn't I be allowed to keep it?"
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Because its a controlled substance. :p
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Sorta undermining your own argument there aren't you? :D
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Twat! :lol: Umm, no, WMDs are definitely different from firearms. You don't use WMDs defensively. (Except in MAD, and that's a bit dicey, we don't like doing that.)
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I knew you were going to go there. Which is why I looked up this (http://www.dangerouslaboratories.org/radscout.html) link. I presume that assuming he could have kept the danger of leaks down that you feel there is nothing wrong with that story?
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There is a difference between a danger of high radiation levels, and a danger of an intentional sustained chain reaction. What's your point? One is a weapon, the other isn't. :p
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The US has had experimental rail guns for a while now, and they are starting to reach a lethal capacity ...but I'd say its at least a good twenty years or more before you see one deployed.
Considerably sooner than that, as a 155mm model is to be installed on the DD-X, which is due in within the next 10 years or so.
I think it's already been demo'd out at White Sands.
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My point is that if you feel that there is no reason an object should be regulated simply because of the danger it may be to others if it is carelessly used or intentionally misused then you should have no problem with someone building a breeder reactor in their garden shed.
As long as they don't commit the crime of actually leaking radioactivity it should be okay, right?.
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Qualifications to run such a facility safely? And who watches it when they're asleep?
I suppose the point I'm making here is that there has to be some kind of sliding scale based on the danger of the object and the difficulty of cleaning up after it.
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My point is that if you feel that there is no reason an object should be regulated simply because of the danger it may be to others if it is carelessly used or intentionally misused then you should have no problem with someone building a breeder reactor in their garden shed.
As long as they don't commit the crime of actually leaking radioactivity it should be okay, right?.
I would have no problems as long as they knew what they were doing... but being able to know that... hmm.
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In other words both you and ngtm1r are saying that dangerous items can be allowed in the hands of the public if there is sufficient regulation to ensure that the public will be safe?
Kinda different from the point you made earlier about allowing anyone to build weapons and only dealing with any crime committed using them surely?
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My point about them building weapons was not that it was fine and dandy... my point was that these weapons are freaking regulated... and they acquire / make them despite our best efforts. If they focused more on actually punishing those who commit crimes, rather than slapping them on the wrist and figuring they're just misunderstood, then maybe they'd get the message.
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Well I agree with that. I just wasn't seeing that from your original comment.
Ya, well, in NY, they regulate crossbows and throwing knives, too... not that it helps much. Do they wish to regulate steak knives? What about when someone puts together their own crossbow? I think all you need is heavy consequences for using weapons in crimes.
Surely that should be heavier punishments for weapons used in crimes as well as heavier punishments for building the weapons without any legal right to do so in the first place?
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Why should it be illegal to build a weapon? Slingshots can be quite deadly, you know. I'd draw the line at weapons that can be used to kill or hurt large amounts of people... those, you should need a special permit for, up to a certain point... and maybe keep the weapons at a secure location (I'm thinking M-60s here). OFC, nukes are out of the question. If you want to build those, go work for the government.
Exactly where would you like the weapons ban line to be drawn? Slingshots are OK? Crossbows & throwing knives? CO2 pellet pistols? Air Rifles? .22s? What? Because you know they (criminals) will just take it to the next level, until you make it not worth their while to build weapons, by enforcing stern punishments for crimes.
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Surely the sensible line is that if you can't buy one you can't build it yourself either?
That ignores all the second amendment nonsense the Yanks are so fond of and works for pretty much any country.
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That sounds appropriate, I guess. :nod: (well, the first line anyways :p )
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Surely the sensible line is that if you can't buy one you can't build it yourself either?
Sounds like a road map for technical stagnation.
Simple fact is the law wont prevent people from doing dangerous things so long as they have free access to the tools they need. The nuclear boyscout incident is not the first (nor will it be the last) instance of someone putting household items to a potentially disastrous use.
Meanwhile, locking up every new technology before its reached its potential (just because there are irresponsible people in the world) limits the number of minds able to experiment with solutions to a problem.
Worse it gives people an excuse to regulate tools that have nothing to do with weapons, simply because they could be used to make dangerous things.
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Can we bring one of these to school?
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Can you bring a CO2 pistol? OK then.
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Surely the sensible line is that if you can't buy one you can't build it yourself either?
Sounds like a road map for technical stagnation.
Simple fact is the law wont prevent people from doing dangerous things so long as they have free access to the tools they need. The nuclear boyscout incident is not the first (nor will it be the last) instance of someone putting household items to a potentially disastrous use.
Meanwhile, locking up every new technology before its reached its potential (just because there are irresponsible people in the world) limits the number of minds able to experiment with solutions to a problem.
Worse it gives people an excuse to regulate tools that have nothing to do with weapons, simply because they could be used to make dangerous things.
So building a nuclear reactor in your shed is fine with you?
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I suppose the question that raises in my mind is why build one?
If you're after protecting your property, then a normal gun is fine, if you're after improving your skill or performing in competitions, then you can try anything from catapults and bows to rifle-shooting. What purpose does building one serve other than to find out if you can, and once you have, why not simply dismantle it again, after all you've proved you can do it?
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(http://img.photobucket.com/albums/v74/GenoStar/topic.png)
That thing looks awesome.
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Er.... this IS on topic, we are still discussing the gun and it's merits/dangers.
Which is actually quite odd after 2 pages in Gendis.
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It seems to be moving away from the "check out this cool railgun" idea, and into the whole "people should/shouldn't be allowed to own anything that's dangerous" idea.
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As for its merits... er... um... it doesn't use gunpowder?
As for its dangers... well... er... at the moment, there aren't any significant dangers. In the future, however, railguns will be highly effective as weapons of war.
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(http://img.photobucket.com/albums/v74/GenoStar/topic.png)
That thing looks awesome.
@BloodEagle: Don't forget to pull up, though! And, get these (http://www.hard-light.net/forums/index.php/topic,49326.0.html).
(http://i14.tinypic.com/4zldav7.png)
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You see, THAT'S what off-topic looks like :p
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This thing makes me wonder if I will see a war with laser guns in my life time. If they can get a laser gun working so that a common soldier can carry it will be a new revolution of the warfare, probably rendering lots of weapons obsolete.
Mika
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This thing makes me wonder if I will see a war with laser guns in my life time. If they can get a laser gun working so that a common soldier can carry it will be a new revolution of the warfare, probably rendering lots of weapons obsolete.
Mika
Until someone starts wearing mirrors. :lol:
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So building a nuclear reactor in your shed is fine with you?
Actually I'm alot more comfortable with the idea of a well meaning bloke making his own breeder reactor and having an "oops" than I am with the thought of them selling a pallet of household cleaner or fertilizer to someone with ill intentions.
Just because some common chemical or item includes no buzzwords does not make it safer for society as a whole.
So yes in my ideal nation sometimes a building will burn down by accident and occasionally someone will short out the cities lights with his new invention... but accepting the risk has lead to a number of Steve Jobs and Burt Rutan types who innovate and make our lives more interesting. Making plenty of good for the damage they sometimes cause.
What good is living in fear gonna do?
You cant expect everyone to walk around in a bubble of government protection their entire lives.
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Well funnily enough I prefer to live in a world where the government know exactly who is in control of a nuclear reactor in their own country. If you consider that to be excessive government interference there's really not much I can say to that. :D
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How much does this thing weigh? And does it actually use a clip?
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Well funnily enough I prefer to live in a world where the government know exactly who is in control of a nuclear reactor in their own country. If you consider that to be excessive government interference there's really not much I can say to that. :D
What makes things inconvenient for you is this is a world where they tried to be in charge of all the nuclear materials and reactor making know how in order to prevent exactly such a thing as what happened.
So we got all the troubles of regulation, spent the money for it, made mountains of paperwork, had the spooks eavedropping on scientists and doing lord knows what else... but we did not get the security this was all intended to provide.
Thats a bad deal.
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How much does this thing weigh? And does it actually use a clip?
No, no clip... I"ll quote the article for you, look at the first post again.
EDIT: Done. Now, there should be no need to actually visit the site. I am sorry for aiding and abetting laziness, but what can I say? :p
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(...lasers...)
Until someone starts wearing mirrors. :lol:
High enough energy density, and the glass melts and the metal surface on/below it vaporizes.
So unfortunately no, tin foil hats/suits will still not save you from the government. :p
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...Yeah.... the Ruby laser (IIRC) actually functions by bouncing a laser back and forth between two mirrors, one of them intentionally a bit weaker than the other. The laser eventually breaks through the weak one.
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(...lasers...)
Until someone starts wearing mirrors.
High enough energy density, and the glass melts and the metal surface on/below it vaporizes.
So unfortunately no, tin foil hats/suits will still not save you from the government.
At that point I would expect that the prices of the diffractive elements would drop drastically, they are probably the only thing that might have a theoretical chance to divert such a beam. But try to keep them clean in a combat environment.
Besides, wouldn't it be much more funnier to clean the lens of the laser gun rather than opening the gunpowder based weapons and cleaning them?
EDIT: Bad typo with tags
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Ya, well, in NY, they regulate crossbows and throwing knives, too... not that it helps much. Do they wish to regulate steak knives? What about when someone puts together their own crossbow? I think all you need is heavy consequences for using weapons in crimes.
In York it is legal to shoot a Scotsman with a bow and arrow on Sunday. :D
/Serious Really cool, if the projectile is 12x heavier than a bullet and 30% as fast that equals more killing power.
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12x heavier than a pellet and 30% as fast. (Pellets are .177 (in.) or 6mm (I think... or 8mm).)
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(http://www.nukelol.com/lolwut/1188197924507.jpg)
I want one of those cute furry animals there sweet, kind of reminds me of my girlfriend, (not) lol
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Trouble with lasers is that the vapors they produce at the surface of the target material actually blocks the beam
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Also that laser (weapon scale) actually does points out the shooter. AFAIK - given the amount of energy output - even if the power of the laser wouldn't be high enough to cause air to ionize and cause 'linear lightning' type effect it would still be more than enough to heat the air on the laser's path making the shooting and especially the shooter visible to any IR sensor. Almost worse than tracer.
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Artillery fire also points out the attacker.
Theres such a thing as counter battery fire where you can be attacked shortly after firing because the enemy had the means to track your shells.
The major benefit of a laser today is the fact it has no real windage or trajectory to worry about. Which makes pulling off extremely difficult shots much easier.
So if you want to do something like shoot a missile in flight (where anything with the striking force of a .22 pistol is plenty and vapor buildup is a non issue) this is about as perfect a weapon as you can find.
Only problem is powering the thing.
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The airborne laser is a chemical laser, it doesn't use electrical power.
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Regarding lasers, one big problem with using them in warfare (as lethal weapons) is their complexity. Guns are relatively simple things, and anyone trained in using them can fix a jam and whatnot without too much difficulty. Not to mention they're pretty sturdy, so it's not a big risk of having a problem with one. And should a gun be rendered unusable, so what? There's certainly plenty more available due to low construction costs.
Lasers are fare less simplistic in their operation, and any number of malfunctions could occur that could take an unreasonable amount of time to fix, if it's even fixable at all. Also note that powerful lasers require a pretty powerful cooling system, and that can make them heavy/bulky. Not exactly something I'd want to use as a soldier, though admittedly they're pretty badass. ;7
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Lasers are fare less simplistic in their operation, and any number of malfunctions could occur that could take an unreasonable amount of time to fix, if it's even fixable at all. Also note that powerful lasers require a pretty powerful cooling system, and that can make them heavy/bulky. Not exactly something I'd want to use as a soldier, though admittedly they're pretty badass. ;7
They work like a charm when tasked with shooting down projectiles, if the THEL is any indication. But it's just as you described, the amount of technical support coupled with the exotic chemicals and complexity of the overall device mean a truly mobile version is a long way off, demonstrated by the slow progress of the MTHEL. Fact of the matter is that bullets are 3 cents a pop, and unless that changes anytime soon, we won't be seeing handheld lasers for a good while yet.
Although, i'd love to see what a THEL could do to a human being... :drevil:
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I think the ground based lasers would be extremely effective as anti-aircraft artillery batteries. They can be also be aimed with visual sights so no problem of alarming anyone with a radar lock and so it is definetely worth a thought at least. It will be interesting to see what practical difficulties there will be in constructing such things. The efficiency of laser systems is generally not very high, if one doesn't count semiconductor-type lasers, so the soldiers' version of a laser rifle is difficult at the moment. Tracked version might be easier to implement.
I'm not sure about the vaporization problem, lasers are used in welding and cutting processes already.
Mika
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(http://img.photobucket.com/albums/v74/GenoStar/topic.png)
That thing looks awesome.
That's... genius.