Author Topic: Portable Coil Gun (Read 8094 times)

Admin · « **on:** May 10, 2009, 08:32:57 PM »

Not exactly robot related, but involves the same knowledge to make it. He apparently made it in a week. It also has a ~2% efficiency, so has lots of room for improvement!

http://hackedgadgets.com/2009/05/07/mv-coilmaster-mark1-coil-gun/

MV CoilMaster Mark1 coilgun - Featured on Hacked Gadgets

SmAsH · « **Reply #1 on:** May 11, 2009, 12:38:44 AM »

owch, ive always wondered about coil guns and making them, but never wanted to go near that sort of power..
this guy is good, and his gun is good too!

BANE · « **Reply #2 on:** May 11, 2009, 06:57:05 PM »

Nice, i'm not %100 sure on how a coil gun works but thats pretty cool how it sucks the projectile from the magazine

SmAsH · « **Reply #3 on:** May 12, 2009, 12:35:28 AM »

a coilgun works by inducing a VERY strong magnetic field for a split second which pretty much sucks the metal towards it, when the bullet is around the middle of the coil, the coil has turned off the the bullet keeps on going...
you getting me? search howstuffworks.com for some info...

TrickyNekro · « **Reply #4 on:** May 12, 2009, 08:21:24 AM »

Ok!!! Physics guy here coming....

I need to check it out first.... I had a though that it may be the same cause a capacitor blows up....
But I gotta check...

HDL_CinC_Dragon · « **Reply #5 on:** May 12, 2009, 01:46:43 PM »

Capacitors blow up when they allow current to jump the dielectric in between the terminals.
And smash is correct. The capacitors quickly energize the electromagnetic coil which, as smash said, generates an incredibly strong EMF(Electromagnetic Field or "B Field" for the electrical engineers) which sucks in the slug. The coil nearly instantly loses its EMF when the capacitors are discharged(also almost instantly) and so the projectile continues on.

SmAsH · « **Reply #6 on:** May 12, 2009, 03:29:18 PM »

they're actually really interesting machines, aren't some division of the army working on something with coil guns?
i hear they have nearly no recoil and can shoot very far... maybe it was railguns they were working on...

HDL_CinC_Dragon · « **Reply #7 on:** May 12, 2009, 05:35:38 PM »

Coil guns and rail guns are the same thing pretty much but yes, there is military research going into these. There is currently a military one (Last I checked, could be more advanced by now) that uses a 2 million volt coil to project a tungsten spike about 1" in diameter and like 14" long or so at super sonic speed towards its target. Theyve gotten it to go through like 6 feet of steel plates or something like that from like a hundred feet away or so. I havnt been following the project so im not sure where they are at with it today.

SmAsH · « **Reply #8 on:** May 13, 2009, 12:23:12 AM »

wow, i never knew they were the same

railguns use two oppositely charged plates to do something...
railguns use a coil... railguns are generally much bigger than coil guns...

TrickyNekro · « **Reply #9 on:** May 13, 2009, 04:18:20 AM »

Quote from: HDL_CinC_Dragon on May 12, 2009, 01:46:43 PM

Capacitors blow up when they allow current to jump the dielectric in between the terminals.
And smash is correct. The capacitors quickly energize the electromagnetic coil which, as smash said, generates an incredibly strong EMF(Electromagnetic Field or "B Field" for the electrical engineers) which sucks in the slug. The coil nearly instantly loses its EMF when the capacitors are discharged(also almost instantly) and so the projectile continues on.

Dragon sorry but you are wrong... Capacitors blow up because the dielectric wants to get away from the capacitor....
We use dielectric to store more energy... But in physics, a systems wants to have the least energy it can...
So it forces the dielectric out... to store less energy....

This is the true why... for sure...
And I suspect that at the coil gun, a lot of magnetic lines are forced through the material but this material
actually instantly is polarized through some microscopic phenomena of the atoms and electrons radial speed, and
this polarization needs energy... so the material (projectile is pushed out)
Try a magnet in the coil gun.... Polarized correctly or not... if correctly centered... It would go nowhere... (in fact it tends to increase it's volume... but it doesn't.....)

End of physics lesson...

paulstreats · « **Reply #10 on:** May 13, 2009, 04:57:58 PM »

Quote

but this material
actually instantly is polarized through some microscopic phenomena of the atoms and electrons radial speed

Very qualified statement made there.....

It happens because the metallic bolt is attracted towards the electromagnet(coil). the coil switches off and the metallic bolt continues (this is said above).

Quote

Try a magnet in the coil gun.... Polarized correctly or not... if correctly centered... It would go nowhere...

I would need this proving to me.... I believe that if the electromagnet(coil) is stronger than the physical magnet (which is more than likely) than the physical magnet will move.

TrickyNekro · « **Reply #11 on:** May 13, 2009, 05:12:38 PM »

I said I don't know and I'm not sure.... so.....

I maybe excused....
But still have to check it... And sorry I can not qualify more cause of my lacking english... :p

About the second quote... It feels you have a point... but...
Cause difference is what makes movement happen.... Still.... I have to check...
Cause I had a talk with a physics guy that told me:

Imagine you have a huge magnet... Very strong and imagine that the magnetic lines are vertical...
Now imagine a small magnet on top of the first magnet that is electrically fired (an electromagnet...)
You also suppose that the magnetic lines are vertical to the first magnets surface (meaning that the
electromagnet and huge physical magnet lines are parallel...)
And asked me... what will happen....
I said... it will theoretically move...
And he said... No... The electric magnet with tend to "blow out" himself... but nothing will happen... no worries about polarity also...
He gave me and explanation but I don't remember it right now... I'll be asking...
Same thing with coil gun... so I have a base to tell what I say....

Generally, movement is caused out of differential... So I'll be asking for more details and write down a qualified answer...
But I feel that what I told above.... in a bad scientific manner.... is actually right....

So long...

SmAsH · « **Reply #12 on:** May 14, 2009, 12:18:24 AM »

i think if the electromagnet was stronger it would "win" against the other magnet,
imagine two forces pushing against each other, the strongest will win...

BANE · « **Reply #13 on:** May 14, 2009, 05:14:04 AM »

any idea where to buy capacitors that size? I was looking on you-tube and some guy made one with just a coil of wire an array of standard capacitors. It would be a cool project to mount one of these guns on a RC tank or something

SmAsH · « **Reply #14 on:** May 14, 2009, 05:56:20 AM »

have you seen that bi-ped who's name i cant remember with the coilgun and flamethrower?
my local jaycar sells ones bigger than that for about $40 a piece. but smaller ones can be done too

BANE · « **Reply #15 on:** May 14, 2009, 06:48:45 AM »

the one that shoots bbs and uses its arm to reload its gun? Rovana bot or something, it was awesome

. it looked pretty heavy with all the commodities and had trouble walking.

paulstreats · « **Reply #16 on:** May 14, 2009, 11:34:27 AM »

It would be cool to use a marx generator as a way of charging lots of very small capacitors(in parallel) and discharging them into the coil as a single capacitor(in series) - with sparkgap bridging and everything down the length of the gun.

SmAsH · « **Reply #17 on:** May 15, 2009, 01:33:04 AM »

http://www.evosapien.com/robosapien-hack/marcus/html/flameosapien_v2.html
it was a modded robosapien! i like the way the bb's are reloaded, smart idea!

Admin · « **Reply #18 on:** May 30, 2009, 08:54:57 AM »

Its all about the right hand rule!

http://images.google.com/images?q=magnetism%20right%20hand%20rule

Blue is the electric field direction, creating red, the magnetic field direction.

In the Navy they do multi-stage coil guns . . . but if the timing between each stage is off, the thing tends to blow up . . .

TrickyNekro · « **Reply #19 on:** May 30, 2009, 10:44:25 AM »

It's what John showed below...
The projectile acts as a short... So It's forced out of the caliber to enable the whole system store less energy....

After all.... everything is physics.... Including weapons....
We did a lesson at mole physics and learned that global warming is actually caused by lack of cosmic rays and not Co2 gases....
Suckers... Smart people... think only of learning.... Dumpa$$ only think of money..... Plus everyone trying to survive...
This only makes you wanter where you belong...

idee17 · « **Reply #20 on:** June 01, 2013, 03:13:33 PM »

Would making the projectile out of an alloy that has a high magnetic saturation point make the rifle more efficient? I suspect that the coil, when firing, reaches the saturation point of the projectile very quickly. So creating a stronger field would not increase velocity by a significant amount, unless the projectile hadn't reach saturation point yet. Is this correct?

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Author Topic: Portable Coil Gun (Read 8094 times)

paulstreats

paulstreats