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Using EMP To Punch Holes In Steel
angrytuna writes "The Economist is running a story about a group of researchers at the Fraunhofer Institute for Machine Tools and Forming Technology in Chemnitz, Germany, who've found a way to use an EMP device to shape and punch holes through steel. The process enjoys advantages over both lasers, which take more time to bore the hole (0.2 vs. 1.4 seconds), and by metal presses, which can leave burrs that must be removed by hand."
Luckily for us, humans aren't terribly good conductors and thus would be essentially unharmed by an EMP.
Sigs are too short to say anything truly profound so read the above post instead.
The capacitors can probably take several million discharges before there's any "wear" on them however the coils must withstand some degree of stress repeatedly which is a concern over the long term due to metal fatigue.
Sigs are too short to say anything truly profound so read the above post instead.
This is not a terribly new idea. I watched video of this technique being used to cut, punch and shape steel over 30 years ago. In fact the video demonstrated punching a hole in steel through a sheet of paper leaving the paper untouched. The only thing that has changed is the technology in the capacitors.
Not all burrs left by a punch press need to be removed by hand. Small pieces may be burnished, rotoblasted, or vibratory finished. Still takes time, I guess.
Due to the physics of fluid dynamics, a urine stream would largely break apart before it would hit the fence its self and thus a current would have a fairly difficult time traveling up the urine stream to you. More so considering that urine isn't a very good conductor unless it has fairly substantial amounts of various salts in it. I wouldn't do it but it isn't *quite* as deadly as it sounds. See mythbusters' take on the matter.
Sigs are too short to say anything truly profound so read the above post instead.
Hi. I'm a metalworking professional, with a heavy background in tool and die work.
>metal presses, which can leave burrs which must be removed
The burr side, if you've got sharp tooling, doesn't have much of a burr. Also, when you assemble the product, the burr side goes away from the user. Speaker grille material, for example, is always mounted on the finished speaker burr side in. If you've got a large burr punching holes in steel, then you have dull tooling and/or wrong punch-to-die clearance.
>.2 seconds per hole
Too slow. Much, much too slow. Call me when it can equal 600 strokes a minute on a conventional press.
>by hand
Someone's never heard of tumbling, flame deburring, electrochemical mass finishing, etc.
>This article is written as if there's no tooling involved and there's no die or stripper plate to back up the steel as it's distorted by the EMP. It goes on to say that it can do away with molds. LOL QUE?
Total misunderstanding by the journalist.
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BMO
The device works because it induces a current in the conductor (steel in this case) which creates a magnetic field which opposes the field that caused the induction in the first place. This is why you could also punch through non-ferrous metals like Aluminum with the EMP "press." The reason it wouldn't punch a hole through a human is entirely due to the fact that we are poor conductors of electricity which means that it is essentially impossible to induce an electric field strong enough to allow the device to punch a hole.
Sigs are too short to say anything truly profound so read the above post instead.
The magnitude of the induced current depends largely on the inverse of the resistance for which steel is magnitudes lower than human flesh. That means that the field would need to be truly colossal to do the same thing to a human being that this punch is doing to the steel.
ionizing EM radiation certainly. Terahertz can also create bubbles in the DNA helix which can impair proper cell division but there is *zero* evidence that the fields involved in the EMP press do any of this.
The punch works because it induces a current in the metal which creates a magnetic field to oppose the one that induced the current in the first place. It does not depend on the magnetic properties of the metal. This means that roughly anything that is highly conductive like Aluminum, 303 stainless, copper etc. could be punched with the device. Largely non-conductive materials like humans can not be punched with the EMP punch.
Sigs are too short to say anything truly profound so read the above post instead.
When I was a small boy, I had a friend who lived on a farm. This lad tried it and relayed to me that it's just as bad as it sounds. (Also, in my observation, urine streams do not tend to break apart, and urine also is VERY salty.)
The government can't save you.
No. The problem with laser cutting is that when the laser vaporizes material off of the target, the vaporized material obstructs the beam to a degree which fundamentally limits the rate at which the laser can cut. Another concern is that lasers aren't the most efficient things at converting power into the coherent laser light necessary to cut through metal. It may be more efficnet from an energy standpoint to use the EMP punch rather than the laser.
Sigs are too short to say anything truly profound so read the above post instead.
The upper limit on a .45ACP is 21,000psi or 1,400ATM.
The "EMP press" generates 3,500ATM.
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BMO
You can only cut so fast with laser do to the properties of the metal under cutting force. Is the old cookies in the oven. Directions say 350 for 15 min so 500 for 6 min is the same thing right? Wrong. If the power is turned up that increase in energy needs to go somewhere. The properties of the metal can only diffuse that so quickly. To fast and you ruin the edges of you blank. Machining 101 BTW
I run a water-jet at a university, but I prefer a laser cutter or plasma cutter for CNC work. The water-jet is a pain to keep running. High pressure air and water, tubes, orifices to replace, mixing tubes that wear out, water filters, etc. Maintenance nightmare. I prefer to just have to clean the optics once in a while on a laser cutter and I can tell you that the laser cutter we have cuts much sharper than our water-jet.
The advantage of the water-jet? Will cut 4" of ANYTHING for one thing, and it will cut the brittles like glass and ceramics and stone that the others will not. Also rubber - I cut a lot of rubber with it.
Cheers.
I doubt it would be very effective. Here's what's happening. A large power source builds up a charge in a bank of supercapacitors. This charge is fed into a coil, generating a magnetic field. The coil induces an equal but opposite field in the steel. The two fields repel each other, and since the coil is fixed in place, the steel under the core of the coil gets flung out of the way.
Now, if you had the large power source, the supercapacitors, the massive coils, and the supply of steel out in space, the whole shebang would indeed be moved by the steel slugs moving away. However, due to the mass of the "engine" and the weak "thrust", the whole thing would be impractical. In short, the device is a coil gun. You'd get more thrust out of a magnetoplasmadynamic device (same basic parts, but vapourize the steel instead of punching out holes. Higher velocity==more thrust).
The main problem, as with all electric rockets, is the power source. You need megawatts of power to get a few hundred measly newtons of thrust. That kind of power source does not come light. You need a nuclear reactor, or hundreds of square metres of solar panels. Massive.
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This, as the article points out, is basically a beefed up version of magnetic forming. Magnetic forming has been around for decades. It's useful mostly for compressing cylindrical objects, so it's used on couplings, tube joints, and similar round objects I've seen it used in making hydraulic spool valves. It's a way to apply a completely symmetric radial squeezing force, which is hard to do at high precision with stamping dies or presses. Here are some examples of parts formed by magnetic forming.
But for punching holes, there's no obvious advantage to magnetic forming.
Why a rail gun? They are awfully inefficient after just several shots your railgun is fried. Build a gaus gun(also known as Coilgun), same idea less friction.
No need to store energy just make use of Explosively pumped flux compression generator. In a few words it's an emp generator that uses highexplosives, single use instant emp.
Third rails are about 750V with lots of amps but animal fences are like 10KV with almost no current. The third rail is a lot more dangerous but the urine path is high resistance.
As someone said, its volts that jolts but mills (as in mA) that kills!
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A better name might be Magnetic Punch. There's nothing amazing about it. They are just magnetising the steel as part of a solenoid. Like a motor or rail-gun.
And yep, it'll still be forcing the steel through a punch tool. So, burring will still occur. Just a case of speed and strength, no different to any other punch.