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Simple Coil Gun 2010-07-05

What is an coil gun? Its an prety fancy way of shoting projectiles out of an tube.It uses magnetic force to do it.Its simply just an coil of wire around an tube that has an iron rod in it.

Heres how it works:

The rod is siting before an coil.Then a pulse is run trough the coil.The magnetic force will try to pull the rod in the midle of the coil.So that makes the rod move.Then we need to thurn off the coil right before the rod has reached the center.Its still moving so it will fly out of the tube.

In order to make it go fast we need lots of curent.And becose it only needs to be a pulse an capacitator is the right component for the job.It will store the charge and then release it all at once in the coil.We also need farly high voltage to get enugh curent trough the coil.

I made an simple coil gun.It needs the corect balance betwen the capacitence and the coil resistance.

Here is what speeds i got:
-12 Km/h whith only 2 capacitors and 1Ohm coil
-27 Km/h whith 2 caps and an 0.2 Ohm coil
-30 Km/h whith 4 caps and an 0.2 Ohm coil

I have made a video of the gun shoting at varius oobjects.(Excuse my crapy webcam)

The video is 2MB,27 seconds and at 30 fps(So you can do freze frames)

Ok next is the construction.
The transformer i used outputed 50 V I then have an voltage dubler that then outputs 100 V.(Each cap is craged to 50V)Then there is some work to be done whith the "FIRE!!!" switch.Do not use an normal stitch becose it will be destroyed! In my case the switch has to take an 500 amp pulse.So i made my own switch fom scrath Its aculy a pice of thick wire that contats an chunk of coper wen i push down the fire button.This all was closed in a cardboard box becose wen i hit the switch an spark almost as bright as an photo flash is made that will blind you.(The switch is not in the photo)

Now the hart of the coil gun! The coil it self.
The coil must be low resistance in order to get enuugh curent trough it.And it also must be made out of thick enugh wire or the coil will overheat.I used 2 m of 1mm coper wire.

Good luck if you try to build it

Oh and here is the part list:
-1: 40 - 70 V mains transformer
-2: 1 Amp diodes
-2 or more: big electrolic capacitors rated for 60 V or more
-1:switch for charging
-Coper wire,cardboard box and duck tape for the fire switch
-Coper wire and a small plastic tube for the gun
-1 or more:Iron rod for an projetile.

Objects fired at in the movie:
1 Litle cardboard box
2 Dry kitchen sponge
3 Platic bag
4 Crunched togeter alu foil
5 Whiteboard marker
6 CD

This is dengerus if you launch it in your eye!!!And be avare that your handeling high voltages (100V)!!! Safety first!!!
Someone Electro
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