# Rail Guns

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youll need a huge capacitor! with a fast duty cycle' date=' charge it from and NST or OBIT and thatll work well, as for the car batt, youll risk overheating it as the current drain to stepup would be enormous! for a workable charge.

failing that, maybe you can get a pole pig from a scrap yard? some have them to burn out and strip the copper, Army/Navy surplus stores are also handy if you can get an old Radar transformer and the caps used in them, all or any should work just fine [/quote']

Whats a pole pig?

Yeah I've heard I will need a capacitor, but I was hoping to get around that by simply having a very very tiny rail gun. Like, 15cm long rails with a penny as a projectile.

I've done extensive google searches on the subject, so I've already seen the powerlabs site, that little em toys one or whatever it was, and a variety of other ones. But they all deal with rail guns way way larger than one I intend to build (aside from the em toys one, but I dont have any super powerful magnets at the moment).

All I want, is a number, in amperes, for getting something the size of a penny moving. Not fast, just enough to overcome friction. Considering the small size, I thought that a car battery alone would be enough for the job, without a capacitor. Is this completly wrong?

Thanks for the input, keep it up!

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a pole pig is another name for a distribution transformer, youll often see them at the top of telegraph poles and with the 2 ceramic insulators they look a bit like a pig

its a slang term used by coilers.

your car bat CAN be made to work, but theres not much in the way of stepup transformers from 12v to several Kilovolts without extensive switchmode circuitry.

youre better of starting with mains elec, then youll find the doors wide open for transformer choice

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a pole pig is another name for a distribution transformer' date=' youll often see them at the top of telegraph poles and with the 2 ceramic insulators they look a bit like a pig

its a slang term used by coilers.

your car bat CAN be made to work, but theres not much in the way of stepup transformers from 12v to several Kilovolts without extensive switchmode circuitry.

youre better of starting with mains elec, then youll find the doors wide open for transformer choice [/quote']

Stepup transformers?

Mains elec?

I do not know what these terms mean.

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Might I suggest making a coil gun again? It is still an EM weapon and would be much more rewarding for a beginner.

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Tycho,

I don't mean to be rude or insulting, but you obviously have a limited electrical background. Even something as small as a penny is going to require thousands of amperes at relatively high voltages. The type of materials and equipment to produce this is dangerous and complicated. There is nothing wrong with experimenting with electrical energy, but only after extensive safety training and basic theory has been understood.

There are many experiments that can be done to show the same principles as a rail gun, and will also provide you with the experience and training to work into larger projects. All I'm saying is walk before you run. Try the Gauss Gun from my link, its lots of fun and very educational. Then buy yourself a basic electrical lab and go from there. Good luck!

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Tycho' date='

I don't mean to be rude or insulting, but you obviously have a limited electrical background. Even something as small as a penny is going to require thousands of amperes at relatively high voltages. The type of materials and equipment to produce this is dangerous and complicated. There is nothing wrong with experimenting with electrical energy, but only after extensive safety training and basic theory has been understood.

There are many experiments that can be done to show the same principles as a rail gun, and will also provide you with the experience and training to work into larger projects. All I'm saying is walk before you run. Try the Gauss Gun from my link, its lots of fun and very educational. Then buy yourself a basic electrical lab and go from there. Good luck![/quote']

Thank you. This is actually exactly what I needed to know. I have no idea on the amount of current required to move a penny, which is what I was asking. I would agree that thousands of amperes is well above the scope of my project. Heh, I wish I hadn't called my project "Rail Guns". Oh well, live and learn.

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''] Heh, I wish I hadn't called my project "Rail Guns". Oh well, live and learn.

Can you still cahnge it?I would the the coil gun idea would be better.

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']Stepup transformers?

Mains elec?

I do not know what these terms mean.

no problem

a Stepup transformer is simply where the 2 windings (primary and secondary) are arranged in such a way that any incoming AC voltage presented to the primary winding will be "stepped up" to a higher voltage on the seconday winding.

Mains elec(tricity) is the power sockets/outlets you have in your house typicaly 120vac or 240vac

to bring the 2 ideas together, the opposite of a step up transformer is a step Down transformer (obvious I know), youve probably used these yourself when you have an electronic device that works on batteries but you can also plug it into "mains electricity" these transformers sometimes known as adaptors will take your 240 or 120 volts and step it down to maybe 6 or 9 volts, theyre usualy black plastic cubes that plug into your house, youve seen then used to charge mobile fones etc...

hope that helped?

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Also in regards to transformers, when they transmit the power down the power cables, the voltage is stepped up to a rather high value (around about 100kV) so that you get a very small current, and hence you lose less heat in the wiring. If you sent power down at 240V, you'd lose a lot of heat

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My recommendation would be to make a Gauss rifle. Have you heard of those? Use standard magnets instead of producing a magnetic field with electricity. Would someone mind giving me a detailed explanation of a rail gun? I know the principle by I mean from like an engineering standpoint, and why it works?

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With a generator in the middle of an occupied area I would imagine having rail gun machine guns on the perimeter would be able to set up a shield of steel. If the range and targeting were able to match the incomming mortars and artillery with speed and quantity then they should be the ideal next generation weapon.

I like some of the examples of transfer of EM energy that are efficient to a point but the fact is we still don't have a really efficient way of making a "very very strong" maintainable magnetic field in a cheap small portable device.

Maybe tommorrow.

Just aman

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Here's probably the best site out there on the subject.

http://www.powerlabs.org/emguns.htm

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this is off topic, but i read about this railgun that they will build on ships in ships that can propel projectiles 300 miles in a matter of minutes.......

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• 5 months later...

does anybody know any good resources on how to make a small coil gun?

Thanks,

Dan

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• 4 months later...

I am doing a study on electromagnetic drag force. A spinning copper wheel is brought near a magnet. The RPM of the wheel immediately slows down. Let's say from 1000 RPM to 900 RPM. How to calculate the DRAG force? The DRAG force has slowed the wheel by 100RPM. How many NEWTONS is that? Anyone can HELP?

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Is the drag force related to the centripetal force?

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I am doing a study on electromagnetic drag force. A spinning copper wheel is brought near a magnet. The RPM of the wheel immediately slows down. Let's say from 1000 RPM to 900 RPM. How to calculate the DRAG force? The DRAG force has slowed the wheel by 100RPM. How many NEWTONS is that? Anyone can HELP?

It's a torque.

tau = I*alpha

I is the moment of inertia, alpha is the angular acceleration

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Is the torque in Newtons or Newton meter? I want the drag force in Newtons. How to calculate I? I can convert the RPM to velocity of the edge of the wheel as I can measure the radius of the wheel. The wheel moves like a bicycle wheel(vertically) and not like a CD(horizontally).

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Anyone who can help further?

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• 3 weeks later...

Can we have a room temperature rail-gun?

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Yeah sure, you can have a rail gun using permament magnets too, doesn't have to be an electromagnet.

A room temp rail gun would work, just wouldnt be a superconductor, which I assume is the main, if not only reason for making a non-room temp rail gun.

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• 1 month later...

I say google "photoflash coilgun", making one is safe enough for a 9th grader, and it's not expensive. If you don't know what a photoflash capacitor is, just check out the guts of your friendly neighborhood disposable camera. They're quite effective for their size.

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