SpudFiles

He used the coils as a chrony. He put a magnet on the projectile and when it went through the first coil it stated a timer and when it went through the second coil it stopped the timer. Since the distance between the two coils is known, it is easy to work out the speed using S=D/T

Hi all,

Jimmy, thanks for correcting me there. Yes 6+4 is not 8.... of course I just wanted to check whether you guys were awake, ahem.

TwitchTheAussie, the coils I mention are purely for measurement. They have nothing to do with propulsion. When a the magnet approaches a coil, the coil will have, say, positive voltage across its two wire ends. At exactly the time when it goes through the center of the coil, the voltage will turn to negative. My electronics detected that, first at one coil and then again at another, 75 cm downrange.

But apart from that, you have an idea. It could be fun to play with a magnetic gun. The only thing is that anything that can store a lot of electric energy and make a fast, controlled release of it, is bloody expensive.

Lukemc, sorry the thing is in one country now and I´m in another. I got it in the "BP (British Petroleum) gas store". It looks like all the others.
I also got a different one later, which is lousy in comparison.
Try with small gaps. Size doesn´t matter here. Neither does the resistance of the wire used ... but insulation does, especially if you run the two wires close to each other! I recommend running the wires (separately) through PVC aquarium hoses.

Regards
Soren

Thanks mate and yes electromagnet guns are expansive but a tonne of fun. And thanks for clearing that up for me mate.