Can you build a diy low-energy railgun

Power shouldn't be an obstacle if designed correctly. You just need a bank of capacitors.

And if it's going to "haul stuff really far" it's going to be considered a weapon by any local law enforcement.

Long story short, you probably don't have the money to build anything that will move anything over a few ounces.

>>1113616
So far, in the past month, we got:
>/diy/ grappling hook (archived)
>/diy/ batman gauntlets (http://boards.4chan.org/diy/thread/1110643#p1110643)
>/diy/ theatrical smoke propellant (http://boards.4chan.org/diy/thread/1112613#p1112613)
And now this.

Dunno about the rest of you, but I'm watching the news with popcorn from now on - it's only a matter of time before some entertaining shit happens!

>>1113616
I've actually built a rail-ish gun. Power is the easy part. Keeping the rails from eating themselves from current arcing is the hard part.

>>1113616
>low-energy railgun
Is that anything like a low yield thermonuclear bomb? Or honorary member of ISIS?

>>1113616

A (multistage) light gas gun makes more sense for propelling loads into high altitudes.

https://www.aa.washington.edu/files/research/ramaccel/publications/STA-witherspoonOct2000.pdf

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https://www.youtube.com/watch?v=NJRDclzi5Vg

>>1113672
Btw if that is your first electroboom video, know that he plays an idiot, he isn't actually one. He is a Canadian electrical engineer

>>1113674
*citation needed

>>1113678
He gave a tedx talk

Here's another interesting idea that's kind of related ; http://hackaday.com/2016/09/22/electric-train-demonstrator/

This one would be good if you had a lot of wire, batteries and magnets, since it would be easier to just use batteries as a power supply.

Saw a video in which someone had a pipe with a coil in it and shot at some fabric and measured the speed but now I can't find the video.

>>1113688
>tedx
If an idiot talks to a room full of other idiots, is he less of an idiot? Paradox.

>>1113741
Not what i was suggesting, i was suggesting in that video he cited all of his qualifications

>>1113625
>And if it's going to "haul stuff really far" it's going to be considered a weapon by any local law enforcement.
Please read your fucking laws before spewing bullshit.

>>1113628

Hey the lobster overlord thread was pretty good.

>>1113616
>So i have been researching for a while and came to the conclusion that its possible.
Of course it's possible, the real question is if you can shoot a projectile with a significant velocity
And i highly suggest using electromagnets to generate the field

>>1113616
>>>/k ????

>>1113616
>low-energy
>railgun
Pick one.

>>1113650
>low yield thermonuclear bomb
neutron bomb

>honorary member of ISIS
Hillary

>>1113616
480v 3-Phase Generator by Miller or Lincoln. Should give you sufficient power to fire a .50 slug or smaller for good effect.

What are you trying to destroy?

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>>1113616
>low-energy

>>1114308
Nothing, really. Got into the topic trough a video.

But since im in europe its gonna be frightening weapon in the great race war to come.


But anyways, thanks guys. Will make another thread if i make progress

>>1113628
>>1114221
Op is preparing to fight a one man war against the lobster mafia

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Maybe make a gun that shoots live lobsters, OP.

>>1114463
>>>/pol/

>>1114501
>But since im in europe its gonna be frightening weapon in the great race war to come.

No, it won't. A weapon is the answer to the specific target you want to destroy.

You can reverse engineer IEDs from training materials, but that's /k/ stuff. EFPs and expedient claymores would be fun to play with.

>>1114501
I think a bow and arrow or even a slingshot are better choices to slay niggers and mudslimes

Of course it's possible to make a railgun. You can do it with a battery, two strips of aluminum foil, a flat surface, some copper wire, and a nail. For a bigger one, check out:

https://www.youtube.com/watch?v=vAs9EHtKfVc

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>>1113616

>>1113652
My dick makes more sense for propelling loads into high altitudes.

>>1114272
>>1113650
Shut up idiots, a rail gun of only a few joules is totally viable

I discovered how to build a small scale railgun, but I need one thing solved to check it's viable. Basically peak amps need to be so high that even 10 miliohms becomes an issue and requires thousands of volts to overcome. But I can't find the formula for how many amps I can push at various voltages.

Assuming 1000A and 1ohm how do I calculate the minimum voltage to push 1000A through 1 ohm?

>>1114973
ohms law little boy.

>>1114973
It takes 1 volt to push 1 amp through 1 ohm,so 1000v to push 1000a through 1 ohm

>>1115013
https://www.youtube.com/watch?v=SBCw4_XgouA

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I think this should work in theory if you can keep it below 0.1 mohm. Basically most railguns have to run very high voltages because all the wiring between capacitors and the rails adds up to several mohm.

Instead of using film capacitors you could use thousands of ceramic caps mounted directly to the rail itself. Using these mouser.com/ProductDetail/TDK/CGA9P3X7S2A156M250KB/ a 100x100 array results in 10,000 capacitors in a rectangle plate around 50cm x 30cm x 0.6cm. A stack of three gives you 30,000 capacitors and perhaps 200,000uf around 100V.

Square plates aren't very efficient in size, I made it that way to make it easier to see. If done properly the caps would be in layers of radial arrays directly around the rail. 600,000uf would probably fit in that layout. The capacitors weigh about 14kg per 200,000uf

Of course the problem is the $60,000 worth of capacitors, but a more modest version not trying to match the energy of firearms should be possible.

>>1115089
>I think this should work in theory if you can keep it below 0.1 mohm.

You can't. The contact resistance of the projectile and/or plasma arc are going to have more resistance than that.

Also, you realize that, even if you get a deeper discount than a full reel's worth of those offers, you're still looking at OVER THIRTY THOUSAND DOLLARS worth of capacitors for your 3-board array. I guarantee you can get better bang for you buck (perhaps literally in this case) if you were to blow that much money on high-quality, larger capacitors.

>>1115090
>but a more modest version not trying to match the energy of firearms should be possible.

The 0.2F version won't come close to matching a firearm as it is. After factoring in the miserable efficiency of a railgun (2-4% is typical), you're looking at something more in line with an airgun, at best. A toy slingshot would pack more of a punch.
@OP: There's not much point in a "low power" railgun. Coilguns are generally much better suited to low projectile energies. Not that you're ever going to make eitherl, if you actually had to fucking ask:

>how do I calculate the minimum voltage to push 1000A through 1 ohm?

Jesus Christ, you don't have a clue.

>>1115122
>You can't. The contact resistance of the projectile and/or plasma arc are going to have more resistance than that.

Forgot to mention: The high voltage isn't just there to overcome resistance, it's also there to overcome the parasitic inductance present in the whole circuit. A large array of capacitors on a board will likely have more of that than a few large ones, by the way.

>>1115123
I found a few studies testing smaller railguns BEMF was minimal on a 1.5 meter barrel. It spiked at the end but was minimal on something like a 0.5m rail.

The projectile resistance should be ok, the one I drew is only 2mm diameter you would use something like a 200mm long tungsten dart with the normal U shaped aluminium sabot. The magnetic forces bend the U shape aluminium into the rails so there's no gaps.

>>1113616
>and came to the conclusion that its possible.
Holy shit, YOU CAN PROVE RAILGUN THEOREM? Up till now it was entirely theoretical, no-one's actually managed to put current through two nails and drop a fucking bb on it!
But seriously, power supply? Some big fuck off capacitors.
Rule of thumb, capacitors 100x the size of whatever you wanna shoot out of it.
As for payload, anything organic will get crushed to mush, anything, fuck, anything other than a solid element's not gonna survive the trip.

>>1113616
You could probably send a microsatellite into orbit with one. However you'd need like a mathematician, physicist, mechanical/electronic engineer to run the numbers.

>>1113628
>And now for your six o' clock news
>Later yesterday a man wearing bladed gauntlets and a batman suit was shot with what police are calling a 'home made rail gun' while he was attempting to climb the side of an apartment building while screaming "I am the night". The owner of the rail gun said he was told how construct this weapon on the 4chan board 'do it yourself', who presumably were responsible for building the 'internet hate machine' used by the eponymous hacker Anonymous. More at 7

>>1115232
It would take a railgun a mile long to make orbit without incinerating the cargo from acceleration. There is only so much force you can impart to an object before that object vaporizes.

>>1113616
The answer is no.

>>1113616
how far is really far?

>>weapons-class gun
well if you don't need super high speeds then there is no reason to use a railgun.

>>1113688
>He gave a tedx talk
Can you give a link?
I tried googling but the best I could find was a makerfaire video.

>>1119627
I assume >>1113688 meant this;
https://www.youtube.com/watch?v=ZxBF7WC0TQk

Ruskies living in holes did it in Metro 2033 with random shit so I am sure you can figure it out.

>>1114939
but totally worthless...
At these energies airguns will easily outperform it

>>1115089
most railguns run at high voltage because E=1/2CU^2
Energy rises exponentially with voltage, so to a certain degree, it's better to go high voltage then high capacity

I think it is hard work to make a high voltage. It is essential for exerting great Lorenz force.

>>1120123
>>1120126
Just use a tazer then.