coil gun help!

i am building a coil gun and i need help. what is a good material to use for the barrel? a Pen tube? i did a test using on cap and it went about six inches with barely any wire for its coils. how fat do you think i can get a small nail going with 4 caps at 300v at 450 uf? also, does the projectile have to fit snuggly in the barrel. i am using magnetic wire from a motor taken apart. so, how many windings should i have?

sort by: active | newest | oldest
guyfrom7up9 years ago
To Tech-king: I promise I will not make any HV projects. What's RCRL? Resistor Capacitor Resistor Inductor? I'm making a wireless power inductive power transfer device thingamagij, that doesn't count, right? Tank Circuits, yummy.
resonant capacitance, resonant inductance. basically a tesla coil or other resonant transformers or frequency generators.
ohhh, you mean to resonatley (the adverb of resonant) step up voltage to insane levels. I'm just using resonant coils to transfer power without wires efficiently.
guyfrom7up9 years ago
I cannot find your comment, please start up here lol
guyfrom7up9 years ago
oh, and fewer windings of fatter wire is better up to a certain point. The more current the better. Windings X current = magnetic field. So calculate the resistance of the wire. 0.1 amps with 100 windings of 30 gauge is worse than 100 amps at 1 windings of a thicker wire, like 10 gauge or something. And since you are using it for a coil gun, faster is better, so use the fattest wire until the internal resistance of the capacitor is what's limiting you. Use fat wire for everything from your capacitor and forward.
the thicker the better, because its the amps that do the work. a coil gun works by sending a nearly unlimited ammount of amps for several seconds. capacitors are great for this application. thicker wire has a higher circumference, allowing more amps to flow (the higher the amperage, the more the amps wick to the outside of the wire)
tech-king9 years ago
the expert has arrived: oscar!!! (cue theme song) 1) the barrel should be thin but sturdy. brass is good. 2)nails are not functional rail gun shapes. you cannot use round or pointed projectiles. 3) the projectile should fit reasonably well in the barrel. 4) just add more windings. eventually, the enough becomes too much and you lose velocity. when that happens, ease off. 5) guyfrom7up, try adding silicon glue to your cap leads to prevent arc over.
guyfrom7up9 years ago
I tried making a coil gun, but I got scared when my caps started arcing, fusing metal together, and then I thought to my self, and this is going to be close to my body. The tube should be a thin as structurally possable. The projectile should fit kinda snuggly, it should be able to move really easily, but don't leave a huge gap between it and the barralel otherwise the magnetic flux doesn't influence it as much.