Railguns
 

Greetings everyone.

I'm doing some research involving Lorentz force-based electromagnetic propulsion systems (railguns), and was wondering if anyone had any experience with them. I'm looking for resources that I can use to build my own, and hopefully once I get everything up and running I'll be able to post some pictures to the forum.

Right now things are in the pre-pre-pre-planning phase, with me just hunting and gathering info. Any advice in terms of power supplies, materials, construction, and whatnot?

one source might be to llok at some of the new rollercoaster designs. they are starting to use electromagnetic forcr for quick accelerations. maybe that type can be bumped up for more power.

my advice: don't bother, you won't get a projectile up to any decent speed unless you have some beefy electromagnets and power source, not to mention firing systems and a decent projectile.

if you do decide to go with it however, it's gona be pretty big, and it depends on what type of propulsion your going for. if your just using magnets placed next to the barrel, it'll be pretty straight forward, but you'll have some problems with getting them to fire in order, however, if you plan on spiral magnets, good luck to ya:p

Here are a couple of sites with info on the subject.
http://www.coilgun.eclipse.co.uk/index.html
http://www.powerlabs.org/

http://www.amazing1.com/hv-dc-power-supplies.htm
High voltage power supplies

I just read through the entire rail gun project on that web site. He's doing a great job, I'll have to remember to go back every once and awhile to see more

Hmmm... this is indeed not one of those projects that can be laid out on the shop floor with a chalk marker.

you can get some insta-gib going on after you get it working ;)

I thought this was pretty cool, especially if you have kids...
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A 10 minute railgun

A railgun is a device for accelerating an object by running electric current through it along a pair of rails. When large amounts of power are used, the railgun becomes a potent weapon. But the principles can be demonstrated safely by using a smaller amount of power, in our case, from a 9 volt battery.

When a small amount of power is used, the rails can be re-used many times. If larger amounts of power are used, the railgun becomes a one-shot device, as the rails are destroyed in the process of shooting the gun, due to arcing and flexing of the rails.

There are several types of rail gun, each with a different method of accelerating the object. This version is called a linear homopolar motor. (MORE HERE)

You aint kidding there. Somewhere in the realm of 15 to 25 megawatts depending on size.

You can go for an old-school one by using slotted tubes filled with mercury and a U-shaped wire sitting in them. Apply current to the ends, and teh "U" will fly down to the other end.

15 megawatts sounds like a hell of a lot of power to me... I'm going to scribble some calculations on the back of an envelope and see what I find. I don't think you'd ever manage to fire anything heavy. Bolts or ball bearings should be doable, I reckon.

I did see one on a TV programme - it was about a metre long and diameter a couple of centimetres.

I always wondered if you could make a circular one, and get the projectile up to speed gradually. Then let it out.

Here is a pretty cool link I found by a couple guys trying to build one. It would be really cool to have one of these things around the house. Hours of fun for the whole family!

http://www.railgun.org/

Another thing is how are you gonna stop the projectile. These things fly FAST, you dont want it to go through 10 of your neighbors' houses before stoping.

Well, if you are shooting one of these things, chances are you don't really care about making it stop so much as making it go, but a shit ton of snad bags and a couple of concreat walls would be a good start. Or you could try to put it through a swimming pool. Water will slow shit down real fast. Unless you are using supercavitation, but that is a WHOLE other can of worms.

http://www.angelfire.com/on2/snakesd...talgearrex.jpg

A railgun you say?

indeed... but I can just see somone aiming down into their swimming pool, and watching the projectile skip off the surface and take out the neighbours dog. Or similar.

How would you go about controlling the electromagnet sequence? that would be tricky wouldn't it?

You know, this may sound wrong, but i would pay good money to watch someone put around through the neighbours place from a rail gun. Just the look of shock on there face when Rex disapears in a red mist. Don't get me wrong, I like dogs, but still.....

As for the sequencing, well, really, I got no clue. I'm sure they got some sort of nifty timeing circute or something you can use, but that is not my area. I'm just a bored guy who likes to read a lot, so I've picked up a few thing here and there.

You can control the sequence by having the rail separated into different sections, and use the armature to connect each area as it spreads. The other option is to use a timing circuit.

You don't really need a sequence; railguns just require a steady current. That can be accomplished by putting an inductor in series with the capacitors.

To stop the projectiles, I'll probably use a steel backplate put up against a wall. The lab I work in is below ground, so if it penetrates the wall it'll just hit dirt.

Have to make sure to post messerments on the size of the hole....

Cool! Someone posted that scitoys.com site. When he said railgun, that is the first thing that came to mind. I've been to that site, and I love lots of his projects. If my children were older, we'd probably be doing some of them...the site has been already bookmarked for future fun =).

a wile back i saw a show detailing weapons of the future. The US govement has an active Railgun project with a working Prototype that reaches Hypersonic speeds. the Projectile Resembles a current Anti-armor cannon round. It is Depleated uranium self sharpining sabot, incased in a retangular shuttle that separates soon after leaving the muzzle of the weapon.


on the show they fired it Quite impessive.. they are already looking at ways to cram the whole system in to a tank. they even showed a CG modle of a proposed design.


very cool and very high tech