SpudFiles

has anyone ever bult a coil/rail gun before, and if so do you have any pointers for one made out of a camera flash??? how do i get multiple flashes to fire sequncially??

I have not made one.
You could use photogate activated transistors... I don't know.

what's a

photogate activated transistor

?

or a contact sensor, easier. the projectile goes half way into the coil, then it trips the sensor and the coil turns off so the projectile will keep going instead of staying in the coil

A 'photogate' sensor is an Infrared Emitter and Detector Lined up on the sides of the barrel, right after the main coil. Once the projectile has made it through most of the coil, it blocks the Infrared Light from being detected, thus cutting the circut. Once this has happened, the projectile maintains its forward velocity without it being impeded by the magnetic field drawing it back in. Now the projectile is free to continue out of the barrel or into another coil/ IR sensor in a two-stage setup...

Have the projectile be a switch. It would then double as a railgun. Just make sure the projectile switches the coils pretty far back.

Darkerweb12 : '... maintains its forward velocity without it being impeded by the magnetic field drawing it back in ...' .
I know that there has been some fantastic advances in various fields of bio-engineering,but when did they make potato's magnetic?

Looking back, nobody mentioned it being a potato. Maybe we should make it clear what kind of ammo he is thinking of using.