Gauss rifle demo

[The Thing]

Here's a link to a site that shows how to build a gauss rifle demo model. it's not much but it does demonstrate the principle of how even low power magnetic fields, in alignment and working in series, can get something moving.

http://scitoys.com/scitoys/scitoys/magnets/gauss.html

I heard a report that the US army built a tested a gauss cannon in nevada using the side of a mountain as a target.

It supposedly took them 6 weeks to big the round out of the mountainside, it went in so deep, and they had to do it carefully to avoid causing a collapse. I'm not sure I believe it completely, but it is possible.

 

[JustinInOz]

That is a great demo. Thanks for posting it.

 

[Anthony]

Here's a link to a site that shows how to build a gauss rifle demo model. it's not much but it does demonstrate the principle of how even low power magnetic fields, in alignment and working in series, can get something moving.

It is not, however, particularly similar to how a gauss rifle would work.

I heard a report that the US army built a tested a gauss cannon in nevada using the side of a mountain as a target.

It supposedly took them 6 weeks to big the round out of the mountainside, it went in so deep, and they had to do it carefully to avoid causing a collapse. I'm not sure I believe it completely, but it is possible.

This sounds like a tall tale. First of all, any round going as fast or faster than a conventional bullet will break apart on impact with the side of a mountain, and thus not be recoverable at all; the bullet itself won't go more than a few dozen multiples of its length into stone. Secondly, you can drill through an awful lot of mountain in six weeks. Third, why does the army care if a section of the side of a mountain collapses?

That said, there is research being done on electromagnetic cannons, though I believe it's mostly being done by the Navy.

 

[The Thing]

http://www.defensetech.org/archives/002514.html

Mach 7 muzzle velocity, 300 nautical mile range.

 

[The Thing]

It is not, however, particularly similar to how a gauss rifle would work.

.

There ARE some major similarities. The basic principle is the same: Each magnet in a linear accelerator accelerates the projectile to a higher speed that the one before it because it's accelerating it from the speed the others already boosted it to, hence it's a series of cumulative effects adding up to a lot of speed.

 

[BlackBat242]

Yes, but it is self-limiting.
As the round spends less time in each successive magnetic field (due to increased speed), each field affects it less than the one before. This means that just extending the length of the barrel to fit in more magnetic fields quickly becomes an exercise in "gun is getting much bigger, but bullet goes very little faster".

Each combination of barrel diameter and round length will have its own "best barrel length/speed", with those rounds that are longer compared to diameter going fastest (due to having more time where part of the round is in the magnetic field)... until it gets so long that it is two fields at once, which causes lots more problems!

 

[aramis]

Actually, the twin-strip system is the standard railgun design, from what I've read, and at some point, friction does overcome added gains. Difference is that the nominal railgun puts the contacts on opposite sides of the projectile, rather than under... and the voltages involved generate mach 3+ projectiles.... but the magnets on he projectile are expensive.

 

[JustinInOz]

G'Day Guys,

I do not think that Thing was proposing that Gauss rifles in Traveller are made with 4 magnets and a wooden ruler. (Back me up here Thingy . . )

It is really cool that some of the principles involved in a sci fi weapon can be so readily demonstrated.

I am sure that a tech level 13 weapon would have a different set up for the magnet positions , compensators for friction, barrel length engineering et al.

However if anyone can show us a link to a clip of a better designed one, I am all ears.

 

[deniable]

You might find something on coilgun.org.

The biggest problem I have with the original link is that you have a series of magnets/balls banging into each other and going faster. It kinda has a perpetual motion feel to me.

And a high-tech version would use a plastic ruler.

 

[whartung]

Actually, my favorite display of magnetism is in an old pinball machine.

Back in the day, some of the machines had the feature of "magna-save", where they place a powerful magnet under the playfield, and the player can press a button turning it on. As the ball came by it would jiggle to a halt just above one of the flipper lanes. Mind, these magnets were REALLY strong electro magnets, as pinballs are pretty heavy.

Anyway, the most spectacular example of this use was in the pinball machine "The Shadow" (themed after the movie with Alec Baldwin).

At the top of the play field, there's a drop down target representing a door to a secret room.

When you knock three times (i.e. hit the target three times), a magnet kicks in and stops the ball. THEN, the target drops down, opening the door, and finally, the magent momentarily releases the ball (which starts to roll down the sloped playfield) and then pulses back on, accelerating the ball in to the chute. Then the target is reset.

It's a very eery effect, and quite clever. Very fun to watch.

 

[The Thing]

You might find something on coilgun.org.

The biggest problem I have with the original link is that you have a series of magnets/balls banging into each other and going faster. It kinda has a perpetual motion feel to me.

And a high-tech version would use a plastic ruler.

Well, the site explains that you can't make a PM machine from this and explains why.

And a really high tech version would use a teflon ruler...

 

[aramis]

And it makes an aluminum foil railgun, a couple pages on.

 

[sburchett]

Ah, pinball machines... they led to my transition to video games.

It is the "distant" past since I have played real pinball, but I do remember those super-powerful magnets in some of them.

Mata Hari was my favorite table.

Steve

 

[aramis]

Black Knight was my favorite table.

 

[G. Fieendish]

Re: Pinball machines
For a practical demonstration of magnetism on player's nerves the Addams Family & Twilight Zone machines were perhaps the best...
(The Twilight Zone was especially sadistic, as some of the balls were made out of plastic, and therefore were immune to any "magna save" features....).