Introduction: DIY: How to Make a Coilgun From Disposable Camera With Flash
Introduction
This tutorial will show you how to make your own coilgun from disposable camera’s with flash. It looks difficult but it’s easier than you think. I have built this thing for my physics school project and I’m still kind of busy doing research on how to get higher speeds of the projectile. It seemed fun to upload my tutorial with the steps on how to make this dangerous thing!
If you don’t use the optional stuff that is indicated by the ‘what you need’ list, you can build a cheap, portable coilgun!
-I’M NOT RESPONSIBLE IF YOU SHOOT SOMEONE WITH IT OR IF YOU HAVE BROKEN SOMETHING WITH IT-
Things you’ll need to build this little guy:
-Some disposable camera’s (you can use only one disposable camera)
-A long enameled copper wire of about 0,5mm diameter
-A drinking straw with a length of about 10 cm (choose the length that you prefer)
(you can also use a ballpoint-pen)
-Electrical insulation tape
-Some wire
-Soldering iron
-A light switch
-A push button
-A screwdriver
-A projectile (a small metal object; e.g. a small nail)
-A nice coilgun box (optional)
-Universal circuit board to make your own capacitor bank (optional)
-A voltmeter (optional)
-A black and a red input for the voltmeter (optional)
-Battery holders (optional)
-Stickers to decorate your coilgun box (optional)
-Electronic knowledge & solder skills (optional!)
Assemble the things that you will need and let’s go to the next step!
Step 1: Disassembling Step
The first thing you have to do, is to open the packaging of the disposable camera (of course). When you’re done with it, remove the battery out of the camera. The capacitor might be charged, so watch out!
If you’re afraid to get shocked during disassembling of the camera, just look where the capacitor is and discharge it with a screwdriver. If it gives a nice spark, that’s discharge. You can go further at ease with disassembling.
Disassemble the camera and remove the flash circuit (carefully).
Look for the charging-button and the flash-button that were used to load en trigger the flash. If you have identified it, mark it and solder the flash-button together, so that it’s closed.
The charging-button is easy to identify (on the circuit that I use). Under your flash circuit, you see an iron button and under it you have two copper plates. Remove that button and mark these two copper plates. Solder each plate with a wire. You will need this later for the light switch.
(Optional step:)
Unsolder the capacitor from each circuit board and solder parallel ( + by the + side and – by the – side ) on a universal circuit board. When you’re done, solder the + and the – side of a capacitor with a wire and reconnect it with the place where the capacitor first at the circuit was. You have made your own capacitor bank!
Step 2: The Coil
Unsolder the flash tube and the reflector attached to it(VERY IMPORTANT!) and mark this place. You will need this later.
I early mentioned in the ‘what you need’ list to use a drinking straw. You wind the enameled copper wire around the drinking straw. (You can also use a ballpoint-pen instead of a drinking straw if you want to waste your beautiful ballpoint-pen. I chose a drinking straw, because it’s cheaper compared to a ballpoint-pen.)
How long the coil will be, is up to you. But I recommend to make a length of about 5 cm.
To get a higher speed with this little guy, you must to work in layers. I have eventually made a coil of 1, 2, 4, 6, 8, 10 and 12 layers.(Yes, I’m insane) I took measurements of the highest speed and the coil of 10 layers won, so I recommend you to wind a coil with 10 layers. Less is also fine, but you will not have the maximum speed of your coilgun. I made about 100 windings in a layer with a length of 5 cm.
Insulating the layers with insulated tape is unnecessary, because the copper wire in already enameled. When you’re done, don’t forget to scrape the coating off the end of your coil. This is important when you’re going to solder the parts.
Step 3: Soldering the Parts
Choose a nice box to put your coilgun in. Make a hole for your light switch, your push button, the led, the coil and two holes for your inputs (optional)
Now you’re ready to solder the parts. Here we go!
You need to solder a wire on each of the copper plates of the previously removed charging button (which you have marked). You need to solder these two wires to the light switch.
With some wires (this entire paragraph), you solder one end of the coil to one connection where the flash tube was before. You solder the other end of the coil to the push button. You solder the other connection of the push button to the other connection of the flash tube connection.
(Optional: )
If you want a voltmeter to measure how high the voltage is when the capacitors are loading, solder the inputs parallel to one of the capacitor of the capacitor bank.
(red input by + and black input by -)
Step 4: Time for Testing
You will now have a nice box with a coilgun in it. Let’s test this monster.
First what you have to do is to is to put the battery in it’s the place as usual. (I’ve solder one battery holder extra so that the coilgun will last longer) Put a small projectile in the coil. Then press on the light switch so the capacitors can load themselves. If you don’t have a voltmeter, the led will give light if the capacitors are loaded. When the led is lighting, turn the light switch off and press the push button.
Now you’re done!
Have fun with it! If you have any question, just ask me :')
Video at youtube:

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14 Comments
6 years ago
Hi! I'm currently trying to replicate this really awesome instructable, however, I seem to have a problem regarding the coil. When I connect it to the capacitor bank, all I get is a loud spark from the point of contact. My capacitors all seem to work fine and are able to produce a total ~300v. When connected directly to two AA batteries, my coil works fine and a magnetic field (although weak) is formed. I have a feeling my coil isn't long enough (it's about 5cm long with 4 layers total, 22 AWG), but I'm not completely sure. What do you think?
Reply 6 years ago
Did you find out what was wrong?
Reply 6 years ago
Yeah, it turns out that I was testing it incorrectly. Whenever I wanted to send the voltage through the coil, I would touch both ends of the coil's magnet wire directly to the capacitor, creating a large spark. I later realised that the best way to test it was using an actual switch to close the circuit.
6 years ago
question, what will happen if i dont desolder the flash tube? will it not charge?
Reply 6 years ago
It will charge, but bright flashes and projectiles don't mix
6 years ago
This project is awesome! I had a few old disposable cameras lying around and now I might try to build this. I made a quick video of one of these disposable cameras being disassembled and the capacitor inside being safely discharged if anyone is interested: https://www.youtube.com/watch?v=x4BWi8sUQJ4
7 years ago on Introduction
How much wire did you use on the final coil?
8 years ago
where DID you get that box from, ive been looking all over the internet and i couldent find a single box
9 years ago on Introduction
Hola... puedo utilizar mas capasitores?
Reply 9 years ago on Introduction
Sí, pero tiene más probabilidades de tener un choque eléctrico
Reply 8 years ago
Claro que existe riesgo, pero siempre y cuando se haga con cuidad, lo puedes hacer, recuerda soldarlos en paralelo. :D
8 years ago on Introduction
Hey there,
That is actually amazing and well built. I just had 2 questions
1. If i want to achieve higher speeds do i need to increase the voltage or increase the no. of layers and keep everything else the same?
2. Where did you get that box from?
thanks
Reply 8 years ago
You should increase the number of capacitors and solder them in parallel.
8 years ago on Introduction
did you really shoot a pannel pin into an orange?
COOL :D