Step 4: Bring It All Together

Now Connect Everything Together. Follow the Picture Diagram and Schematic.

Test the system, if it works use Plexiglas, wood, or even metal to make housing for your gun depending on the desired size/weight etc.

The Battery Banks Must not exceed +3V for relatively safe operation.
<p>Btw i once saw a 15kJ 2.5V capacitor somewhere for around 800$, would that even work? (probably in a line so they make some more volts and 100mm&sup2; wire)</p>
<p>I got a 385V/2200&micro;F (163J) capacitor, and got a small coil (~0.2mm wire diameter) to fire an iron core half a meter far (it was charged to ~25-44J), so a thicker coil would surely work?</p>
I am having some trouble im trying to do this with an electric weed eater any advice
<p>Electric weed eater.. well, I'd suggest to put that down, and try using the suggested components instead. Good luck!</p>
<p>does someone knows how to charge a capacitor?</p>
<p>apply current</p>
Sorry again, decrease*
Sorry again, decrease*
Would it decrease charging time if you were to use more than one charging circuit, turning them on one at a time, and having them linked in parallel to the bank?
<p>I have fawned a way to make the coil gun a automatic. I put a lm555 timer ,but you can use any of the 555 chips, to make it a automatic gun.</p>
If you were to make a coil gun with just a single disposable camera circuit, you would just need to apply the power bank to where the battery would have gone, with a switch also on the positive wire, and apply your coil (with your lever switch on the positive wire) to the capacitor. (positive with positive, negative with negative) now if you used eight circuit boards,( keeping in mind on how I explained a single circuit board coil gun works) line them up in series, with each capacitor removed from them and put into a separate bank, the boards would all receive power evenly, which in turn, provide the power to the capacitors. My point is that nobody has to even follow this tutorial when they can simply do this, for one, you wouldn't have to destroy a perfectly good circuit board, and two, this way also allows you to use ANY KIND of circuit board as long as each one uses the same power source. Lastly, why would you want to waste so much money on building the guns body and/or case, when you can simply use the body of your choice water gun, nerf gun, etc. The inside of one is bound to have enough space to hold everything, and you can paint it the color of your choice when you finish putting it all together. That way it can save you the hastle on buying, finding, wasting much MORE money on the things to make one.
<p>There's actually a very good reason you don't connect he boards and caps in series, that is because they wont balance correctly. Each cap has a different capacitance, it can be off by only a few microfarad or off by hundreds of microfarad, regardless, if you put them in series, the lowest value capacitor will stop charging first, and current will cease to flow through the loop at that point. (findamental property of a capacitor is that it stops allowing current to flow once it's charged) This is not a big problem if all your caps are almost identical, because you will get pretty close to the correct voltage on each capacitor. But if you're using cheapo disposable camera capacitors, then odds are your bank will stop charging long before every capacitor is fully charged. The solution is to use an active balancing solution, or a microcontroler, that systematically monitors the voltage of each cap and drains and charges them as needed to maintain balance. But that is an expensive and involved solution, the better method is to put them in parallel. <br>Further, you dont gain any power when putting them in series over parallel</p>
<p>the soloution to this problem (caps in serial unbalanced) is to use the voltage divider principle. just put on each cap a low-tolerance reisistor in parallel. This will make sure that each capacitor will be charged. Please google the math for the right resistors.</p>
<p>i am in a country that dont have exactly that cameras :P soo i cant easy make this and i need to know WICH coil-magnet wire i need can someone pls send a link to me? &lt;3 thank you </p>
i also wanna give thanks to instuctables user Plasmana. without his idea on his worlds smallest electronic shocker, i wouldnt have been able to use this idea for the coil gun charging circuit, and have been able to decifer rwilsford07's method.
for those of you who want to know EXACTLY on what connects to what using rwilsford07's technique, i drew up a diagram that'll make it much easier to understand. this way will also allow you to once again, use ANY curcuit board as long as it has all the correct componants shown in the diagram. the best thing about this diagram, if your a experienced solderer, you can desolder the components and solder them together OFF the curcuit board, which is best because it'll allow you to save A WHOLE LOT of space within your coil gun.
Why not just connect the circuit boards in series instead of in parallel, so each board can receive power evenly, and without having to cut out ANYTHING as well. You can make a simple cheap coil gun from a single camera circuit board without having to or cut anything.
<p>how to manualy connect a kodak ( disposeable camera ) transformer to wires to connect to the transformer and get high voltage?</p>
<p>I'm not sure for that application, but I made a taser like that.</p>
<p>Did u actually brand it with FESys</p>
<p>who knew you could build a futuristic deadly weapon for 200 bucks</p><p>i doubt it actually shoots tho</p>
<p>Does this work?!?!?!</p>
<p>how many batteries do i need?</p>
rwilsford07, may i ask your email?
<p>hi uh what kind of capacitor did you use i' new to this so i'm not really sure, i know it isn't a super/ultra capacitor but if you could give me a link to a similar capacitor to the one used in this instructable that would be helpful thanks</p>
<p>I think I'll try this project this weekend.</p>
I have got myself two types of disposable cameras (FUJIFILM and Polaroid). <br>I can't tell where to cut the circuit board (and what the transformer looks like) so that the transformer comes out. <br>If It's not too much trouble could someone draw on the photos where I need to cut. <br>Thanks.
The circuit board with the red LED. Do I need to cut it with the Transformer?
When you say the capacitors should be rated 300VDC...<br>Do you mean each capacitor or all the capacitors in the bank must equal 300VDC to 900vdc?
Each capacitor.
the design bears striking similarity to that of a high power emp device, will the gun emit an emp pulse when fired? http://www.wikihow.com/Build-an-EMP-Generator - (link to wikihow that shows how an emp device is created)
Where else can I get charger circuits from? A lot of the stores nearby me are not that generous.
I'm willing to bet you get better picture quality with one of those kodaks.
Hey,I'm use circuit disposable fujifilm,how to make it into parallel ? <br>
So I am looking at the semi automatic design, and I was wondering what exactly the injector solenoid did? Also if I used the &quot;Boost Converter&quot; that he also shows you how to build would you need the disposable cameras?
In reply to ishmal1103: <br>It's possible you've heated a transistor too much and it has burned out just replace every transistor but be quick and make sure it doesn't get too hot again or it will blow one of them out and then you will have to replace all of them again because you can't tell which one is the dead one (make sure when you get a new transistor its matches the one on the circuit board or it wont work e.g. the circuit board one might be negative positive negative (npn) so you will need to get a npn and not a positive negative positive (pnp) you can search up how to test between the two.
Hey, I recently managed to obtain a few pretty large capacitors (3x 3300uf 350v to be precise) and I was hoping to build one of these, I was just wondering if someone could recommend what size coil I should use and possibly the addition of more stages?
The theory behind coil guns is that they create a large magnetic field momentarily that accelerates your projectile, either through or away from the coil. The strength of the magnetic field is determined largely from two things, the amount of turns your coil has and the amount of power you push through it. You want the smallest wire gauge possible that doesn't liquify under the current you force through them in order to pack as many turns into your coil as you can in a given size. <br> The overall size of the coil is really up to you. You want the inner diameter to be slightly larger than your projectile. I wound mine around 1/2 pvc pipe and used that as a barrel. I hate supporting Radioshack, otherwise known as &quot;The Man&quot; when it comes to hobby electronics, but they usually sell magnet wire in the back that has a small enamel layer and is perfect for winding coils. Mine was roughly 2&quot; long and only about 1/4&quot; thick but worked great. <br> <br> Those capacitors hold a lot of energy( E=1/2*Capacitance*Voltage^2 ) just over 600 Joules fully charged by my calculations. A simple design would be to just charge them up and discharge them all through your coil. In order to add more additions it gets more complicated with light triggers and high voltage transistors, but totally possible with something like an Arduino.
Is the DC to DC HV Boost converter a substitute for the camera chargers in parallel? Sorry about the stupid question I just want to make sure.
do coilguns require high voltage or high current <br>
Wow bro, you get everything i use from the same places. CVS 'cause i can ride my bike there, Harbor Freight 'cause they carry everything (including parring knives if i spelled that right and a sextant. and don't forget the machete and foot-long hunting knives!), and Radio Shack for the electrical components. <br>and just wondering, what would change if you hooked up a 2100v 1uf capacitor to the coil? wouldn't the performance turn out to be better? after all, it is a high voltage capacitor.
Not really if your charger charges at 300v and you have a 2100v cap at 1 uF then the cap will be charged to 300v 1uf you would see almost no change
Oh and the projectile would go much faster
You would need to up the voltage output of the charger bank and beef up all the wires. Maybe add some diodes to prevent blowing the chargers, and do some other things to make it work
Anyone have any ideas to replace the camera charging circuits with something more efficient?
No unless you can make capacitors ( which I highly doubt) you can get them at Walgreens though.
It sounds like he was talking about the actual circuit that charges the capacitor, not the capacitor itself. I've always wondered about doing this too.
fascinating, amazing how small you managed to make that SDPA-1 model. for simplicity of building would i be better trying to make a coil gun or rail gun? i have used that circuitry from disposable cameras to produce high voltage before but avoided the capacitors as they deliver terrible shocks if you go anywhere near their electrodes. i don't think i would try for making it automatic, that wasn't very clear how, but i might attempt to build one. great instructable.
please reply to my message