Coil Gun 2

[TheSweaterKid]

you listen to some gay music bro

[qwertyboy1234567899]

that's about 350 joules

[ChangeWasALie]

The fire button is uncomfortably close to the two capacitor leads. 300v + 7000 micro farads would be one nasty shock.

[jedin2]

what is a coil made out of?

[bobdavis321]

The coils is three layers of about 15 turns each of AWG 14 enameled wire.

[JuStsme0nE123]

i really like this vid

i used probablly the same thyristor, a GE B1589. looks a lot like it

and what a capacitor bank!

what is ur voltage?

[bobdavis321]

That model was only 320 volts, it is a voltage doubler off the 120 VAC. I do not remember the SCR model number.

[HVdischarge]

"only 320V" you wont say that if your thumb goes across it :-P lol.

Nice bank. Ive just built a 400V, 6000uF bank with a 240A SCR (which has blown once and been raplaced).

scared of going any higher with the voltage!

[Plumfire2]

how does this all work?? can sum1 explain. is it like a charged magnet that when current is turned on the object gets repelled quickly?

[bobdavis321]

It is a electromagnet that attracts a metqal object. Then the electromagnet turns off and the metal object keeps on going.

[Larsplatoon]

Nice coilgun.  I also like your music!

[theroastedpotatoman]

can you send me the scematic of the charger?

[bobdavis321]

The schemaitc is at geocities(dot)com/bobdavis321

It is basically 2 microwave oven transformers with their primaries in series, so they only deliver 1 KV. There are 2 Microwave oven diodes one to each secondary then a 500 ohm 10 watt resistor to the capacitor bank.

[Krumlink]

What's the Joule Rating of that thing? I am planning on building a 1kJ Coil gun myself.

[bobdavis321]

It is no where near 1KJ. It is more like 50 Jules. I have a 800 volt model, it shoots bolts almost through a soda can. I hope to make a better coil that can shoot through a soda can.

[Krumlink]

What I meant was I am building one rated to 1kJ, sorry for the confusion. I laughed when you were shooting the ceiling :)

[bobdavis321]

I think maybe that device was 500 Jules, I dug all over to find where I figured it out and could not find it. Anyway the 8 capacitor model is by far more powerful. Using SCR's may limit the actual current.

[Krumlink]

E= 0.5*V^2*C

E=Energy in Joules

V= Voltage (the V^2 means square it)

C= Capacitance in Farads

[bobdavis321]

Is thats about 250 Joules then? That is based upon there being about 25 x 220uF capacitors, (some are 330uF) and 330 volts.

[Krumlink]

Where do you get your SCR's? I have been looking around, but I haven't found any cheap ones. (about 400V to 600V rating, 2000A rating)

[bobdavis321]

I have been using 100 amp SCR's. The SCR block in my latest 800 volt model is a 250 amp, 1200 peak AMP model. I buy them on Ebay!

[scolen3]

HOLY SHIT, can thtat kill you?

[bobdavis321]

I don't think it would kill you but it sure would do a lot of damage!

[scolen3]

LOL, well lets hope you or anyone does not find out.

[eugenekhf]

hi there, cool and informative video.... i have a few questions to confirm with you...

firstly, the coil, is the wire wound up in a single direction or does it goes the oposite direction when doing the second layer. my coil just magnetise it...

secondly... my caps, does yours run on a series or parrallel?

thanks....

[bobdavis321]

The coil is all wound in the same direction. The bolt must be just outside of the coil to be attracted to the coil. The caps are in a parallel series combination. got to geocities and find bobdavis321. The schematic is on the opening page. -Bob

[michaelcrichtonfan]

i am currently building a coil gun, and i have a question... What exactly are you using for a switch? a transistor? what type? or did you use a mechanical switch? and once again what type of that...

[bobdavis321]

I was using a big SCR rated at 1600 volts and 100 amps. Now I am rebuilding it with a SCR block rated at 1800 volts and 250 amps. The schematic is on my geocities web site.

[FABLE96]

nice stuff their. im planing on making a coil gun myslef. my day is gettin me some copasiters from work dont know how they r or rated but cant give up free :P. anyway im confused on how to wrap the coil it self i look but they arnt realy clear... do u wrap a layer and just rewrap in the oposet direction or do u pull the wire back and start at the beggining agean?

[bobdavis321]

The coil is three layers of 20 turns of #14 enameled wire. Each layer is covered in glue and dried before the next layer is wound. There may be pictures on my website do a google for bobdavis321 to find it.

[gar0017]

does this sound like George Lucas to anyone else here?

[newtonianbarf]

do i spot a tesla coil secondary?

[bobdavis321]

Yes I also have a tesla coil, the video is here somewhere. There is also a dual vacume tube tesla coil around somewhere, but no video yet. Stand by, I am building a 900 volt pwer supply with much more power.

[newtonianbarf]

560 joules! nice.

[TomE1123]

to check if it's charged you usually lick the wires right?

[bobdavis321]

That would kill you. Use a voltmeter, or just test fire it.

[penguinsquishy]

hahaha *buzzap* yup, it works! Kudos to your capacitors btw, Bob.

[girrrrrrr2]

only 28 capisitors...get 25 of those huge capisitors...that would go through that wall i bet!!!

[bobdavis321]

Last week at the Rochester hamfest I picked up 14 5,700 uF at 400 volt capacitors. I hope to make a much more powerfull device with them.

[pinkpalm0000]

I should really get back into the sciencey stuffs; not that i could ever abandon my writing--but this stuff's just so FUN, y'know?

I once tried to build a tesla coil. Some kit from some magazine; it smote itself and spewed brown juice. More recently I've been interested in magnetics--i oncedesigned in my head something not unlike magnet motors, and have had a lingering fascination with maglevs & coil guns.

ANYWAY. Excited to see what you'll do with these new capacitors :D

~Palmer

[omni721]

slingshots, bud... fire an 8mm lead sinker clean through one of those soda cans of yours...

cavemen win again.

[bayerischerzustand]

moar tiberium

[girrrrrrr2]

...more power!!!!more!!!

[bobdavis321]

I have thought about fileing a bolt so it is pointed. That would be work though.

[daydream91]

make a half automatic coil gun thatd be cool!!...

[bobler12345]

That coil gun is sweet! should have used a projectile with a point though!

[2fingertreatment]

pretty damn cool