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[ein]

Hey guys, I've been thinking of building a portable coilgun for quite some time now.
I figure that the first step is finding a power source.

So, electrical engineers, I ask you, what would be a good power source?
I've been thinking of lead-acid cells because they can be made at home fairly simply, don't suffer from memory decay, have a decent energy density and voltage, and it fits in a bit more with the steampunk aesthetic I'm aiming for.
I would use lithium ion cells, but those seem like something that I would not be able to make at home, and I don't want to screw around with a laptop battery or something.

[SHAD0Wdump]

I have but one suggestion: Point away from face...   That is all.

[ein]

I have but one suggestion: Point away from face...   That is all.

Remote Firing Mechanism.
For the prototyping stages, of course.
Easy to build, easy to use.

[Virex]

I doubt you'll get enough power out of a lead-acid battery, but it'll be worth the try. I'd see if you could get some car batteries and hook them up to a capacitator of some sort. Hopefully they'll discharge quickly enough to load the capacitator up fully.

[ein]

If there's a problem with power, it'll more be having an effective battery and capacitors in a compact design.

I'll test the car battery capacitor thing.
I'll probably also reread my stuff on electromagnetics and maybe even start work on schematics.
Honestly, the biggest issue with this project is that I'm fifteen and the person I live with isn't gullible enough to just go buy me copper wire, capacitors, lead plates, etcetera, or even let me go buy it for myself.
Probably because I've been openly talking to a friend of mine about making gunpowder, napalm, and poor man's liquid nitrogen.

[Il Palazzo]

Batteries are a no go. You won't get a high enough current from these. Capacitors are your only option - I hear that you can salvage some from disposable cameras.

[ein]

You can also make tasers out of disposable cameras.
But, will a capacitor operate without a main power source (battery)?
'Sfar as I know, the answer is no.

[Siquo]

It's sad, when a young man's scientific interests are stifled by fear and ignorance...

Also: Short circuiting or overcharging lead-acid (or even a lot of types of) batteries can make them explode. Be very careful if you're working with high energies.

Palazzo: I think he wants to use batteries in conjunction with capacitors.

I also don't know what you made before and your experience level, but you might want to start off with something more simple but alike, like a Taser.


Edit: GAH ninja'd

[Pillow_Killer]

We made these in uni, that was fun. Dont bother with batteries: Worthless. Okay, maybe you could use them to power down some strapped on laser pointer, but eh.
Go straight for capacitors.

[ein]

I am WELL aware of the dangers of short-circuiting batteries.
As for experience, I've made a radio, flashlight, disposable camera taser (in science class no less), quite a few computers, and a rudimentary mass driver that was more like a maglev than a coilgun.
I've also worked with bases a lot, and, if I remember correctly, acids are less dangerous than bases.
With non-science stuff, I've done a little bit of metalworking for jewelery and a little bit of carpentry, but I'm no good with manual saws and drills. Power saws and nailguns are the way to go.

[Virex]

We made these in uni, that was fun. Dont bother with batteries: Worthless. Okay, maybe you could use them to power down some strapped on laser pointer, but eh.
Go straight for capacitors.

Point is that it has to be portable. Capacitors can store enough energy for a shot or 2, but they drain quickly even when they're not being used. Hence the idea to use batteries, who can store more energy, to charge up the capacitors, who can deliver a bigger punch.

[ein]

Bingo.
And I need a battery that will charge up the capacitors fast enough to be effective.

[Calhoun]

Try reversing the polarity!

(Science-fiction solution FTW!)

OT:
I used to know of a site which went step-by-step in the coilgun making procedure. Too bad Geocities closed (Well, I think it's still a net-gain for the internet.)

When you say portable, Exactly what are we talkin' here. This:http://www.coilgun.info/mark4/home.htm
is portable in the sense you could carry it easily. but needs to be plugged in, at least until the capacitors are charged.

[PTTG??]

Get some really high-quality caps and relatively small batteries that just compensate for leakage. Make these into one- or two- shot magazines. That way the weapon itself will have minimal weight and you can easily carry much more power.
 
Hold on, I'm going to have to draw this out...

[smigenboger]

I may be completely missing the point, but are you suggesting the kind of guns in Artemis Fowl that those goblins use, that shoot literal ammo, but also have a separate cartridge of batteries they use at the same time?