Hi Guys,
I am a third year mechanical engineer and for my dissertation I have chosen to build a rail gun to show that this technology can be used to launch small aircraft.

I am hoping to build it and launch a 3-5Kg glider, but I have a few questions:

1) does the wire used to wrap around the bar have to be insulated or not, surely it will still produce a magnetic field even if it is insulated so could I put a plastic plate over the top in order to lessen the friction of the projectile sliding over the wires?

2) what sort and size of capacitor will I need in order to launch this projectile to an appropriate take off speed.

3) I have seen a lot of demonstrations that use rectangular rails, Is there any advantage of this over say a circular piece of bar?

4) Approximate what length of rail will I need, I reckon I can get away with around 2.5m per rail with the budget I have.

Any help you can give me will be GREATLY appreciated as well as any other good links to sites or anything like that