Magnetic Linear Accelerator
This experiment is a simple way of demonstrating the distribution of the field inside a solenoid and how it effects ferrous metal objects.
This experiment simply consists of a plastic or cardboard tube with a coil of wire wrapped around one end. The coil can be powered by a set of standard batteries. the more batteries used the more powerful the magnetic field will be.
The tube used to for the coil around should be quite narrow. The case of a pen such as a biro is ideal. You can try using different sized batteries and different numbers of turns on the coil to produce different strength fields.
When a metal object is placed part way into the coil it is ready for firing. The metal should be ferrous (sticks to a magnet) and quite small. A metal rod of about 2 - 3mm wide and 10 - 20mm long is best. Something like a small nail or a screw with the head cut off should work fine. If a small rod magnet is used, it will work much better but make sure it's inserted the right way around, or it could backfire.
To fire the coil gun you simply tap the switch. If you press it for too long, the projectile will either stop in the middle or come back out the wrong end. You can practice different methods and different coil and battery sizes to see what results you get. An alternative firing method would be to use a circuit such as the PWM-OCX which can give repeated pulses or a time you can set youself.
The information provided here can not be guaranteed as accurate or correct. Always check with an alternate source before following any suggestions made here.
But when ever I connect the power supply( one AA battery) all that happens is that the wire coil heats up and the magnet jerks inside the tube....
What could be the problem? Should I try using a higher volt battery?
Odin, sounds like your wire is too thin (I used speaker wire, as it was lying around) but I think solid core bell wire is better idea. While u need the wire to be insulated, it needs to be fairly thin. Oh and it aint a metal ballpoint tube is it?
Again, should be obvious, but your coil is most effective when it's tightly wound with as many turn as possible for a given distance of tube and you can only coil in one direction.
Thanks.
The accelerating force is proportional to the current flowing in the coil. What type of batteries are you using? how thinck is your wire?
1. How many times should I wrap the wire around the tube? I wrapped it around once but nothing really happened (the projectile was pulled into the middle of the wire.)
2. Should I use thick wire or thin wire?
3. I'm using two 9volt batteries. Should I use more batteries?
Please answer, Thanks.
Use non metallic items except the wire to build it. Batteries should be physically large (they can give more current) and at least 9V.
John,
At least 10 times. If the projectile stops in the middle it is because you dont release the switch fast enough. You must disconnect power before it reaches the middle or it is pulled back again.
Thick Wire
Larger batteries would be better.
Tried running the batteries in series as well.. Tried 12 and 25 coils.
I can't get it to fire.. Any suggestions?
and.
How many winds per inch?