Anyone on /diy/ know anything about making railguns?
>>900119
big ass capacitors look up on youtube
>>900119
you need an initial force, usually compressed air.
if you load the slug in and apply current you will weld the slug to the rails apparently.
your household power supply will be shit for anything fun. look at diy wind turbines for a generator then connect it to a car engine.
capacitor banks for projects like this will fuck you up. you seriously need to understand the proper procedures and mechanisms for operating, bleeding and grounding capacitor banks before you start building one.
for hv projects you need to be well aware of spark gap distances at operating voltage and maintain proper isolation not only between components but also to you.
oh and don't point it at anything you aren't ready to kill.
A basic pulsed power circuit consists of capacitors, an inductor, and a switch. Add fuses and diodes for component protection.
A simple launcher consists of copper rails held in place by dielectic material and it shoots aluminum armatures.
>>900151
>Aluminum
I thought these things ran off magnetism
>>900208
I can't even justify a response to this... just. wow.
>>900211
It's a legitimate question, from my experience aluminum is non magnetic. Excuse me for not having experience with rail guns.
>>900226
Thank you
>>900119
compressed air and a long barrel is going to be more effective than anything you can build using readily available power sources.
>>900208
https://www.youtube.com/watch?v=H31K9qcmeMU
its a bit like this
except
the magnetic field is produced by the electricity so you don't need the slug to be magnetic.
>>900132
>weld the slug.
Never understood why instead of working around the problem. They attack it directly? Why not coat the outside of the (for example steel ball) with a thou or two of graphite? Wouldnt that be conductive enough to complete the circuit.. But prevent the insta weld you get from the sudden engery rush.
Also I think you only need like 1125 watts of power to shoot 20mm steel balls through lots of objects....
So youre in luck Op. You just need rush current.
>>900119
Ok op, here is something useful if you want to build a railgun. Scratch that, coil gun. I recommend building a coil gun because you don't have to run the electricity through your guide rails. Meaning you won't need to worry about welding your projectile, just making sure the guide rails aren't conductive.
Anyways, lets get started. First you'll need coils. These are the basis of what gets the slug ( Which must be of a conductive material. ) from point A, to point B. ( Probably someones chest. ) You need to wrap coils of conductive metal around a non conductive loop, leaving a large hole in the center for the guide rails and the slug. Like a donut. THe more pases on your donuts, the more voltage it'll need to work but the more powerful it will be. Most people use copper, I recommend it. I also recommend silver though, as it is far more conductive and useful but also more expensive.
Once you've got your coils, legs talk about rails. Teflon works best, its slick and nonconductive. Don't have teflon? Lacquered wood will work but that's heavy. Just don't use plastic. It will melt and probably break your weapon.
Now, your slug. You're going to need conductive slugs, and you should make them nerf football shaped. Why? Because the frontal cone and long tail with fins works well for stability, as your projectile won't be spinning. The best metal for the slug though, I recommend brass or Zinc, both of which are heavy enough for stable flight and pack a punch because you can't use lead.
>>900252
Now, time to talk about power. Because you need the juice. You need a battery or multiple to run through your coils at a time, getting more power through there. Lithium might be the best choice. Charge it with a few thousand watts, connect the circuit at the end of the barrel and viola, sending those jolts of energy through your coils for a millisecond ( Per coil, sequenced as the projectile travels. ) sends your slug through the air like a fucking bullet.
>>900252
>lead not connective.
PSSHU say that to my solder...
just get some super caps. like the ones used in hydraulics... And 4 gauge wire... wrap it about 4000 turns. without a doubt. send a projectile through a tank...
>>900119
German site with some good documentation:
http://www.rapp-instruments.de/index6.htm
Can anyone find anywhere where a railfun has been attached to the end of an actual firearm firing steel core ammo?
>>900242
Railguns suffer from a LOT of abrasion/material transfer between the slug and the rails. Typically, rails are only good for a few shots before they need replace. Coating the slug with anything would be completely useless.
Yes.
400V 1900uF x 8
>>900469
Dont know if Im gonna finish that project because I just got 350V 2200uF caps, 80pcs. Probably not gonna use them all though and the voltage is pretty low. I dont know shit about this thing though, Im just love things that are loud and sparkly
>>900252
Problem with coil gun is that you need to time when each coil activates. But thats just the matter of doing it, bigger problem is the switches.. If ya gonna go bigger than disposable-camera-capacitors then the switches cost a shit ton of money. You dont need any of that on a railgun, the projectile acts as the switch.
Heres a vid of some guys railgun. Fucking awesome.
>>900298
Thanks for the link, too bad I dont kno german. If someone knows english sites it would be much appreciated!
>>900479
Apparently I dont know how to embed youtube
https://www.youtube.com/watch?v=P6RXd4njUg8
>>900119
why do people make railguns and coilguns? they are shit.
>>900683
Why do people have hobbies? Why dont they just go to work, sleep, eat and work more. Having fun is shit.
>>900689
yeah but theay are really shit like really, total waste of money to do all these complex electronics to move a dart that can barely pierce cardboard. Its funny because when i posted vids of people stitting in drones to fly for 10 seconds everyone said lol stupid waste of time and money
>>900691
So you decided to become one of them?
What is the point of a railgun anyway?(Other than how cool it is.) The whole concept seems very impractical compared to rockets.
>>900698
If it worked? Railgun bullets are cheaper, smaller, easier to store, practically maintenance-free and even more difficult to defend against than rockets.
This >>900702
Also velocity. Weapons powered with burning propellant (including rockets/missiles) are limited by how fast the propellant can burn.
So railgun projectile can reach the target faster and are more accurate. They would be more safe because there is no gunpowder.
>>900698
because when you are on a nuclear powered battleship you can pretty much generate as much electricity as you like instead of having to store explosives.
>>900119
Search the internet archive for railgun.org. Cool site, sorry to see it gone.
>>900691
>barely pierce cardboard
my friend made one that went through his car door and it was handheld
>>901230
car door is nothing
you can punch a pen through a car door just holding it
>>901232
Where the fuck do you buy your pens? LLBean?
>>901232
Oh you must have a kia car
>>900217
You get a powerful enough magnet and I think everything is affected since you're really fucking with atoms.
Anyone know if I'm just rambling or half right or something?
>>900698
Less expensive per projectile
Don't have to worry about handling propellant
No warhead, kinetic energy is used.
The navy gun shoots at like mach 7
It's fucking mental.
Go look it up on YouTube
>>901289
The projectile in a rail gun can be completely unsusceptible to magnetic fields, because it's the current that passes through the projectile that creates the field that propels it forward, not the properties of the projectile itself.
To answer your question: materials can be 1) paramagnetic, where they only exhibit induced magnetic poles in the presence of an external field; 2) diamagnetic, which induce a pole opposite to that of the external field, creating repulsion instead of attraction; or 3) ferromagnetic, like normal magnets which have a permanent dipole. Aluminum is paramagnetic, but the effects can be over 10 orders of magnitude weaker than ferromagnets. IIRC, aluminum is used in NMR and MRI machines, which produce some of the strongest man-made magnetic fields.
What are the military ones using for capacitors? Do they use something more space effective than standard capacitors?
>>901301
>aluminum is used in NMR and MRI machines
It is used just as a coil former. Other metals are used as well. The field produced is what you could expect from an air-core coil (run at insane current).
>>902834
The floating frog! That's what I was thinking of earlier, they levitated it using magnets.
>>902814
I actually got to read some interesting papers on this.
They had planned to spend a lot of money developing new advancements in capacitors, but after review and budgets cuts they went with a different idea.
For now they are using very advanced vacuum fly wheels which can act like fast generators converting huge amounts of kinetic energy into electricity fast enough to do insane things. While theirs are custom made, the cost to develop was not much as it used a very old and well established technology. (I really want one)
The long term plan is to let the commercial sector develop better capacitors then buy them off the market like everyone else, with some addition mil spec considerations.
The real interesting part of the papers was the pro/con report of rail gun vs. gauss gun. While the rail gun had many reasons to be picked as the legitimate winner (not that gauss didn't have it own pros) the reports number one reason for picking rail was lack of magnetic drag which prevents rounds from surpassing a top speed.
I forget what the top speed cited was but remember it was a sizable fraction of the speed of light as it was a theoretical upper limit and wondered why anyone would say something along the lines of "the gun is not effective as the rounds can ONLY be fire at the target at 3/4 the speed of light thus limiting it usefulness". I honestly wonder what kind of things they are thinking as at those speeds it doesn't matter the barrel configuration or target's armor, something down range gone go boom in a very big way.
(pic, UK flywheel to power future high energy laser cannons)
Two questions:
First, why the fire if the gun uses a magnetic field instead of explosives?
Second, why using the projectile as the conductor instead of using a larger conductor pushing the projectile (pic related)?
You would need to make the weapon longer to allow aceleration and then deceleration of the conductor (to use it for the next launch), but atleast you won't weld the fucking thing
>>902938
the conductor would weld though.
>>902938
Pic in OP is a railgun. It doesn't use a magnetic field at all.
https://en.wikipedia.org/wiki/Coilgun
https://en.wikipedia.org/wiki/Railgun
The fire is superheated, vaporized portions of the rails and projectile. The high currents involved literally strip the surface of the rails (and projectile) off, boils them into a gas, and heats them until they emit blackbody radiation, aka become fire.
The second question qualifies as "not even wrong." Railguns just don't work like that.
>>903077
>It doesn't use a magnetic field at all.
it uses two. or three?
>>903077
>Pic in OP is a railgun. It doesn't use a magnetic field at all.
Go read the article you linked.
>>902914
If you like flywheel tech search for the one boeing made in alaska a few years ago.
>>903077
There are plasma railguns, there are magnetic railguns. Way to get worked up about it.
>>902914
The Army tried using flywheels back in the 90s since they have the energy density required for tanks, but they didn't work. I would suspect it's due to the discharge rate being too slow.
Railguns are an expensive endeavor. The equipment costs for a personal version is in the tens of thousands just to get enough capacitors to make the system worthwhile. You can rig a camera flash charger to make one a cheap pulser, but you'll only shoot sparks below an energy capacity in the tens of thousands of joules.
