How to make a RAILGUN!

Step 3 The circuit

solder the small switch to the two wires you made in the last step
solder the extra capacitors onto the current on (remember to keep the positive and negative sides together)
solder two long wires to the capacitors
solder the big switch onto the positive wire

Comments

[railgunner94]

by the looks of those pictures i am assuming each capacitor has around 16uF?

[railgunner94]

160uF*

[II AlphanovA II]

should they be in parallel or series?? or in some sort of matrix??

[techno_pig]

parallel. The capacitors add capacitance in parallel - that means higher current on the discharge which means more force on the projectile.

in series the capacitance halves. that is no good. the voltage TOLERANCE increases, but that doesn't mean they will charge up to thousands of volts. capacitors only charge to the voltage you put in.

[zxzero01]

Where do I solder the rest of the capacitators to the wires where the bulb for the flash was?

[electronic boy]

place them where the cap is PS:make sure that the polarity is right

[Kalamazoo]

How do I tell the polarity of the capacitors?

[tbird45039]

neg. is usually marked with a stripe on the side of the cap.

[TopNotched]

I am using a On/Off type switch for my "small switch" (to turn on the charge). When I turn it on it starts charging, but I have an issue with turning it off. Because of disposable camera nature, they recharge right after a discharge (regardless of On/Off  - DANGEROUS / DEADLY for open models if unaware), this is great if I want to fire multiple rounds, but when I want to turn it off.. I want it OFF (after the current charge is fired and the off switch is off ... without removing the batteries)

Can someone explain how I can mod this? It makes sense for cameras, but not for railguns.

[TopNotched]

OK, I figured out my own fix/mod

Use an external battery box and connect + and - to where they belong, but add a "On/Off Switch" on the + wire. Then instead of adding a switch to the charge like stated in step 2, just connect with a wire without a switch.. If done correctly, after charging up, you can turn off the power and will prevent an auto-recharge (unless you keep the power turned on). 

[dylandance]

Did you put the capacitors in series? That should increase the capacitance if that is at all what your going for.

[jfernald9327]

Connecting in series will not increase the capacitance. The capacitance is the maximum amount of voltage able to be stored in the capacitor, and this does not change

[Country dude]

connecting in parrellel circuit makes more quantity of charge, hooking it up in series adds to it every time. EX. if there are 5 campatitors hooked up in parrelel the shock will last 5X longer. if 5 are hooked up in series it will be 5X stronger then one campaicter

[junits15]

that is it because capacitor only charge to the voltage that is inputed to them, the camera board can only output enough voltage to charge one cap so by putting the caps in a parallel it allows the bank to actually be charged all the way. if this is unclear tell me, because I tend to be unclear sometimes.

[Wesley666]

plus, I have no idea for capacitors, but I know batteries in series ups voltage, but in parallel they up current and rail guns run off of amperage not voltage.

[andrew101]

ok, what if you setup a series of switches that can charge in one curcuit, then after its charged disconnect from the charging curcuit and flipping the switches line them up on series. that would increase voltage.

[junits15]

idk if you could figure aout a way to wire that.

[Mw4rD]

what sort of switch is that up the top corner of the thrid picture? is it a 'push to make' or what? im trying to research to make a nice coilgun, ill put up an instructable after i build it.

[JoltBlue]

i have 3 different sizes of capacitors will it still work or will the big ones blow up the smaller ones?

[Jaycub]

It is fine to use different sizes as long as you don't make the voltage too high for the weakest ones.

[geeklord]

So, could we make really big sparks from this miniature capacitor bank using an diea like this?

[Kryptonite]

Hell yes, but make sure that the switch you use is heavy duty, when it welds close from 300v of electricity running through it, it's sort of annoying.

[geeklord]

K, I've got a 250v/3a relay that i got out of a dish receiver(weird, huh?) that i might use.

[junits15]

I always use atleast a 30 amp relay

[Kryptonite]

A dish reciever? Never heard of it, but the relay sounds pretty good from your description, but I don't know what the amperage of the capacitors you would use so I'll that to you. If you want large sparks, but aren't real keen on the getting burnt and the life being electricuted out of you, You should make a Van De Graaff.

[geeklord]

satelite TV box, dish network, either way.... But yea, i might have to look in to the Van de Graaff. I just need a good motor.....

[robodud3]

so were wireing in a seires or parralel here?

[morijo]

It's parallel. By "parallelling" capacitors, we're able to store more charge in them,.. and when all this charge, discharges all of a sudden, it can drive more current through the coil.

[Neodudeman]

lol that's so cool looking.