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How to build a REAL rail gun (One way to wipe out those damn terrorists!)
Jengle and Fatro's Rail Gun Page ^ | Jengel and Fatro

Posted on 07/27/2003 1:18:25 PM PDT by mhking

Welcome to the newly redesigned haven for the rail gun enthusiast. This page covers some of the latest techniques in electromagnetic propulsion, but the construction of a rail gun is a perilous undertaking so use the information contained herein at your own risk. NOTE: In the interest of simplicity vector directions are ignored, it is assumed that the magnitude is as calculated and in the desired direction.


TOPICS: Culture/Society; Extended News; News/Current Events; War on Terror
KEYWORDS: techindex
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1 posted on 07/27/2003 1:18:25 PM PDT by mhking
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To: Howlin; Ed_NYC; MonroeDNA; widgysoft; Springman; Timesink; dubyaismypresident; Grani; coug97; ...
And the decision is....Just damn.

HMB/Bizarre PING....

If you want on or off this list, FReepmail me!

FYI: This has fast outgrown it's original "charter" and become a home for the truly bizarre. An alternative saying/phrasiology is being sought (and suggestions are very welcome!). Also, like it's "cousin list" the B/C list, it has become a high-volume list.


I'm leaning toward "Just damn," on the suggestion of quite a few folks. I won't make a decision until Sunday. (And thanks to all of you for sending your suggestions!)

2 posted on 07/27/2003 1:18:43 PM PDT by mhking
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To: mhking
But vectors DO matter!

Hook up those magnets/wires the wrong way and the launcher might have the launchee for lunches.
3 posted on 07/27/2003 1:20:26 PM PDT by Robert A Cook PE (I can only support FR by donating monthly, but ABBCNNBCBS continue to lie every day!)
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To: mhking
Now I'm getting nostalgic for Quake II.

Hmm, wonder if I could persuade some of my students to build one as a project?

Of course I could. Let me rephrase that:

Hmm, wonder if I could persuade some of my students to build one as a project and still keep my job?

4 posted on 07/27/2003 1:26:04 PM PDT by Slings and Arrows (Decisions, decisions...)
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To: Robert A. Cook, PE
Kewl! I want the handheld version!
5 posted on 07/27/2003 1:28:54 PM PDT by Threepwood
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To: Slings and Arrows
How about a rail pumpkin gun?

Wonder what a pumpking hitting a target at 4,000 m/sec looks like?
6 posted on 07/27/2003 1:30:30 PM PDT by Poohbah (Crush your enemies, see them driven before you, and hear the lamentations of their women.)
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To: Threepwood
Funny you should mention that...Jane's Defense Weekly mentioned in early 2002 that the US Army was looking at manportable LASERS for air defense. A manportable railgun ought to be equally feasible...
7 posted on 07/27/2003 1:31:42 PM PDT by Poohbah (Crush your enemies, see them driven before you, and hear the lamentations of their women.)
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To: mhking

Sounds like a winner to me.

8 posted on 07/27/2003 1:33:36 PM PDT by Riley
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To: Poohbah
Sounds good to me. I wonder what the federal government here would say if I tried to register a electromagnetic railgun? I wonder if I'd even have to. Mind you, hitting an Elk with a projectile moving at 4km/sec might make the taxidermist's job a bit tricky...
9 posted on 07/27/2003 1:35:20 PM PDT by Threepwood
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To: mhking

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.

railgun

Click on image for an animated picture

What you need

railgun materials

Click on image for a larger picture

We start by spreading a thin layer of glue on the base, to hold down the foil strips.

railgun glue

Click on image for a larger picture

The foil strips are then placed on the base, about a half inch apart, and smoothed down with fingers to remove wrinkles. The extra 2 inches is left hanging over one side, to make it easy to clip on the leads for the battery.

completed railgun track

Click on image for a larger picture

Next we attach the battery with the clip leads. We won't worry about battery polarity at this time -- if the gun shoots the wrong way, we will reverse the battery.

filing railgun axle flat

Click on image for a larger picture

The nest step is to file the ends of the coathanger wire flat. This will allow the magnets to stick flat to the ends of the wire axle. If the filing is done carefully to make the flat ends perpendicular to the wire, then there will be less wobbling as the magnets travel down the rails.

railgun wheels

Click on image for a larger picture

Now the magnets are placed on either end of the wire axle. The magnets should have their poles facing in opposite directions. The magnets repel one another when aligned this way, but will still stick firmly to the steel axle. No glue is necessary, as the magnets are very strong.

Firing the railgun

To fire the railgun, just drop the wheels on the rails. They will start to accelerate immediately. If they don't move at all, the magnets are probably not pointing the same way. Lift the wheels, and flip one magnet, and try again. If it still doesn't work, check the battery and the connections.

If the wheels move in the wrong direction, you can either start them at the other end, or reverse the battery.

Click on the photo below to see the railgun in action.

railgun animation

Click on image for an animated picture

10 posted on 07/27/2003 1:35:28 PM PDT by Southack (Media bias means that Castro won't be punished for Cuban war crimes against Black Angolans in Africa)
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To: Slings and Arrows
Hmm, wonder if I could persuade some of my students to build one as a project and still keep my job?

I don't know, but I want to sign up for your class, whatever you're teaching.

/john

11 posted on 07/27/2003 1:37:03 PM PDT by JRandomFreeper (I'm just a cook.)
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To: mhking
Self ping: read later
12 posted on 07/27/2003 1:39:04 PM PDT by MalcolmS
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To: Poohbah
The Navy's looking into this as well.
13 posted on 07/27/2003 1:42:27 PM PDT by Tree of Liberty
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To: Poohbah
Did you see the pumpkin plunkin' contest on TV?

Elegant machines just cryin' for real-gourd railgun solution to throwin' pumpkins a long way.
14 posted on 07/27/2003 1:55:42 PM PDT by Robert A Cook PE (I can only support FR by donating monthly, but ABBCNNBCBS continue to lie every day!)
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To: Robert A. Cook, PE
How to make America great again:

Fire a pumpkin into orbit :o)
15 posted on 07/27/2003 1:56:33 PM PDT by Poohbah (Crush your enemies, see them driven before you, and hear the lamentations of their women.)
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To: JRandomFreeper
Seems like the right way to do it is to start the thing moving (with a spring ?) so the inital movement is assured BEFORE current is applied: the movement reduces the initial current surge when v=0 and simplifies the circuits.
16 posted on 07/27/2003 1:58:10 PM PDT by Robert A Cook PE (I can only support FR by donating monthly, but ABBCNNBCBS continue to lie every day!)
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To: Southack
Now isn't that cool.
17 posted on 07/27/2003 2:03:02 PM PDT by AdA$tra (Tagline maintenance in progress......)
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To: Robert A. Cook, PE
Before you become too enamored with a magnetic solution, consider not only my post above but also the magnetic acceleration factor.

How long would your magnetic rail gun have to be to get any substantial speed improvement in the projectile over existing technology?

18 posted on 07/27/2003 2:03:34 PM PDT by Southack (Media bias means that Castro won't be punished for Cuban war crimes against Black Angolans in Africa)
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To: Robert A. Cook, PE
I like the sabot approach with a large surface contact area so that current densities don't reach a level where welding occurs.

I have to wonder also about the relationship between voltage and velocity. 12 volts at 1000 amps (dc) = 12kw. So does 120,000 volts at 0.1 amp. Of course, arcing could be a problem.

But what do I know, I'm just a cook. ;>)

/john

19 posted on 07/27/2003 2:05:30 PM PDT by JRandomFreeper (I'm just a cook.)
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To: Southack
How long would your magnetic rail gun have to be to get any substantial speed improvement in the projectile over existing technology?

Barrel length isn't the issue: total acceleration is. The higher the acceleration imposed, the shorter the barrel must be for a given velocity.

20 posted on 07/27/2003 2:08:04 PM PDT by Poohbah (Crush your enemies, see them driven before you, and hear the lamentations of their women.)
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