[img]http://www.scitoys.com/scitoys/scitoys/magnets/gauss_rifle/slomo4.gif[/img]

This very simple toy uses a magnetic chain reaction to launch a steel marble at a target at high speed. The toy is very simple to build, going together in minutes, and is very simple to understand and explain, and yet fascinating to watch and to use.

[url]http://www.scitoys.com/scitoys/scitoys/magnets/gauss.html[/url]

They will be banned before the year is out.  It's for the children; you see?

Quick somebody chrono that thing!

cool! now, how do i build an emp weapon? just a small one to bring down UFOs, wouldn't want to fry my car!

The Neo magnets used are very cool and powerful.  These ain't the horseshoe magnets you played with as kids.  For larger and more powerful magnets, check out the site below.

[url=http://www.wondermagnet.com/dev/magnets.html]Wonder Magnets Site[/url]

thats cool i need to try that someday

I was talking to a physicist about 5 years ago and according to him, this toy is actually the basis for space-based weapons research that started in the mid-60's. I mean, space-based weapons we don't officially have deployed.

I dunno? How big is the average satellite defense weapon platform?

Since hardened neodymium is pretty tensile stuff, I would imagine it's some good impact force.

That site has a catalog on it and sells all the interesting parts you need. The ND magnets are cheap.

NIB (or Neo) magnets are made by a sintering process involving neodymium, iron, and boron. It's like pressed metallic powder. They are very [b]brittle[/b]!  Allowing two magnets to come together at full force will shatter them.  Neo magnets less than 1/4" thick should be avoided because they're so easy to break.  Read the information on the [b]WonderMagnets[/b] site.  The smaller ones are fun but the larger ones (50 lbs pull and higher) can pinch hard enough to draw blood.  Ask me how I know.

If you get some Neo magnets, take care not to get them too close to your wallet/credit cards or computer monitor.  Even the small one I have right here (7/16" cube) is slightly distorting the picture on my monitor from 8" away.  

You could easily scale it up.  Get larger ball bearings and use a yardstick instead of a ruler.  Then use pairs of these: [url=http://www.wondermagnet.com/dev/magnet44.html]3/4x3/4x1/4[/url]

The original plans call for 12 milimeter cubes.  That's just under a half inch.  Pairing up two 3/4"x1/4" blocks will give you a 3/4"x1/2" block. And if you're really ambitious and have deep pockets, use layers of these badboys: [url=http://www.wondermagnet.com/dev/magnet5.html]1.5x.375 Blocks[/url]

Can I put a bayonet on that thing?

I wouldn't call that a gauss rifle. A Gauss rifle would have to use Gauss's Law as its operating principal. This device in no way use Gauss's Law.