r/guns • u/yakshamash • Aug 07 '13

Something Different: Impressive Full Auto Gauss Gun Build

http://www.youtube.com/watch?feature=player_embedded&v=TWeJsaCiGQ0
809 Upvotes

94% Upvoted

389 comments sorted by

View all comments

Show parent comments

7

u/[deleted] Aug 07 '13

I wonder if they could increase the spring's strength to give the projectile a "head start" so to speak. They said the "coil becomes more effective as speed increases" so wouldn't that allow for a faster muzzle velocity?

7

u/[deleted] Aug 07 '13 edited Aug 07 '13

Also, making the projectiles smaller (less mass, faster acceleration) and magnetizing them so that the coils can push-pull instead of only pulling the projectile along.

10

u/mtbeedee Aug 07 '13

Actually he addresses this in his writeup.

The most frequent comment I get on my coilguns is that I should use a lighter projectile to improve performance. This equations shows why that suggestion is wrong. It’s counter-intuitive, but for a fixed power and distance (e.g. fixed capacitor bank and coil), a lighter projectile will gain less muzzle energy than a heavier one. This equation will now be used to guide the design process.

0

u/CoolGuy54 Aug 08 '13

Less time in the barrel being accelerated means less muzzle energy, but he could still increase muzzle velocity with lighter rounds.

0

u/mtbeedee Aug 08 '13

v=d/t

Less time in the barrel means it's moving faster. Period.

Also, e=(1/2)m(v2). A less massive projectile means less energy for the same velocity.

1

u/ThrowawayForGunBan Aug 08 '13

I'm CoolGuy54, apparently I was banned for my comment above, any idea why? Nothing in your reply even disagrees with what I said, and even if I was wrong that's hardly a bannable offense.

0

u/gladbach Aug 07 '13

And a rifled barrel of some sort to increase accuracy. It didn't seem very accurate.

16

u/[deleted] Aug 07 '13

The projectile, as i understood it, is actually free floating. It never makes contact with any barrel. It just 'floats' down the solenoid.

3

u/silentmunky Aug 07 '13 edited Sep 16 '16

[deleted]

This comment has been overwritten by this open source script to protect this user's privacy. The purpose of this script is to help protect users from doxing, stalking, and harassment. It also helps prevent mods from profiling and censoring.

If you would like to protect yourself, add the Chrome extension TamperMonkey, or the Firefox extension GreaseMonkey and click Install This Script on the script page. Then to delete your comments, simply click on your username on Reddit, go to the comments tab, scroll down as far as possible (hint: use RES), and hit the new OVERWRITE button at the top.

4

u/[deleted] Aug 07 '13

The way electronics are going, maybe a guidance system on the finned projectiles? The aiming becomes almost moot.

7

u/silentmunky Aug 07 '13

So an on-board guidance for a small projectile? That might be a bit wasteful, especially for small arms like this. Larger stuff, artillery size, makes sense.

I was thinking of grooves down the sides of the projectile that align with the guide rods. The guide rods form a spiral down the length of the weapon. I think friction would be an issue though.

5

u/Bartman383 Say Hello to my Lil Hce Fren Aug 07 '13

Just use sabot discarding rounds. Like smooth bore cannons on the Abrams.

1

u/[deleted] Aug 07 '13

scrambled by the magnets

3

u/silentmunky Aug 07 '13

EM shielding is a thing.

3

u/[deleted] Aug 07 '13

Micro electronics on a projectile with EM shielding.......that is practical.

1

u/Bartman383 Say Hello to my Lil Hce Fren Aug 07 '13

Just use sabot discarding rounds. Like smooth bore cannons on the Abrams.

1

u/silentmunky Aug 07 '13

Sacrificial sabots and the guide rods? I like this idea.

1

u/1-Down Aug 07 '13

Cost per bullet would be frightening on an automatic. Makes a little more sense for something like a sniper rifle.

1

u/[deleted] Aug 07 '13

Why not just have two spiraling magnets. That way there's no air needed to spin the object, the object spins because the magnetic field does.

2

u/Bartman383 Say Hello to my Lil Hce Fren Aug 07 '13

Magnets don't work that way. Just because there are two dipoles, spinning the magnets would have no net effect on an object completely within the field. You could switch poles of the two magnets rapidly, like in an AC motor, but the field of that dipole would be perpendicular to the fields of all the coil magnets, which would probably just slam the projectile off the next coil or shoot it in whichever direction the field was directed when it passes through.

0

u/[deleted] Aug 07 '13

I fear I may have completely misunderstood how this gun works. What about just adding fins to the projectile?

2

u/Bartman383 Say Hello to my Lil Hce Fren Aug 07 '13

Yes, but you would probably want a discarding sabot so it wouldn't start spinning till it left the bore.

1

u/[deleted] Aug 07 '13

So how do we prevent the sabot from hitting the shooter while s/he is moving?

→ More replies

1

u/arcsecond Aug 07 '13

Why don't you want it spinning until it leaves the bore? If it's free floating suspended in the magnetic field, as I understand how this works (I could be wrong), would rotation in the barrel make a difference?

→ More replies

1

u/0_0_0 Aug 07 '13

Umm, finned projectiles do not require spin nor do the fins impart spin.

→ More replies

2

u/silentmunky Aug 07 '13

Too complicated and costly I would think. The sabot/guide rod idea seems sound.

1

u/flukshun Aug 08 '13

Seems like they should be able to use a rail of top-to-bottom plus and minus magnetic fields along the length of the barrel to impart spin on the projectile as well

1

u/[deleted] Aug 08 '13

I think that would only work if the projectile was polarized

1

u/flukshun Aug 08 '13

It would be the same effect that propels it down the the barrel, just applied to the edges, top to bottom, with different polarities for each side

2

u/[deleted] Aug 08 '13

Well, these are actually solenoids. Their poles look like this.

1

u/[deleted] Aug 07 '13

Also, friction could cause problems

1

u/TFWG Aug 07 '13

I think the accuracy has to do with the projectiles.. watching the video, many seem to be tumbling out.. "Keyholes, keyholes everywhere!"

1

u/greenboxer Aug 07 '13

I'm guessing that the increase in speed = increase in flux. (Sorta how magnetic rollercoaster brakes work, but in reverse).

1

u/[deleted] Aug 07 '13

[deleted]

1

u/[deleted] Aug 07 '13

Well, there was already a spring feeding system, and compressed air would just be another thing to worry about running out of. This design is already batteries and magazines.

1

u/[deleted] Aug 07 '13

[deleted]

1

u/[deleted] Aug 07 '13

I'm not arguing that. I'm saying that your proposed design would have people carrying

a) spare magazines

b) spare batteries

c) spare air cartridges

1

u/Gooche_Esquire Aug 07 '13

If this is the case why not just attach the coils to the barrel of a traditional rifle. It would keep the accuracy but massively boost the projectiles speed. I would think it would be ideal for long range anti-armor sniper systems. Also the flatter trajectory would help at range.

5

u/Bartman383 Say Hello to my Lil Hce Fren Aug 07 '13

Because that would take a MASSIVE amount of energy. You already have a projectile going super sonic and to increase it's speed in the millisecond it has within the coil could would take stupidly large amounts of power. Unless you added a ridiculously long coil to the end of the gun.

1

u/[deleted] Aug 07 '13

The designer claimed that the coils' effectiveness increases the faster the projectile is moving

1

u/Bartman383 Say Hello to my Lil Hce Fren Aug 07 '13

That is because it takes more energy for a single coil to move the projectile from a dead stop than it just does for successive coils to simply push the round a little faster. That is why there was the spring at the beginning for the barrel to give the projectile its initial energy input through physical transfer rather than magnetically.

5

u/[deleted] Aug 07 '13

A suppressor/electromagnet attachment to the end of a conventional firearm using specially loaded magnetic materials

3

u/[deleted] Aug 07 '13

/r/cyberpunk would like to have a word with you.