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Multistage coilgun Answered

How do you connect multistage coils on a guil gun. Also what matters for a coilgun the ufs or volts.  


Both. The "ufs" are microfarads, which is a measurement of how much electrical energy can be stored in a capacitor. For examples, a 200μf capacitor can store double the energy of a 100μf capacitor. Volts determine the size of the magnetic field. For most small coilguns, 300-400 volts is a good range. Camera flash circuits are "okay" for charging these. Also, the amperage determines the strength of the field, the faster you dump the energy from the capacitor into the coil, the higher power your coils electromagnetic field will be. Now, if your capacitor is too large, and your switching circuit too slow, not only will the coil pull the projectile back, but the initial forward motion will be significantly reduced. You need a capacitor and switching circuit that will work fast enough to effectively drain all of the energy before the projectile passes the coil. In other words, you need a balance between voltage, capacity, and switching speed. 
P.S For a beginner coilgun, you shouldn't stray above a 2500μf capacitor bank, at 450v. For safeties sake.

Ok, so, to connect multiple coils is pretty easy. First of all, wrap the coils. Next, you need a tiny switch like this, wire so that when you press it, it makes a relay close the circuit to supply power to thecoil. Place one behind each coil so that when the projectile passes it hits it, turning on the next coil. And repeat.

Oh cool! Do you think it would work, or would the projectile be slowed by the switches? Also, how would you turn off power to previous coils...?
I was just browsing google and it turns out that this is a question here....

How would you turn off the coil after the projectile is in front of it in a single stage? Same method. And the switches barely take any force to close, and if its still too bad, you can use an infrared emitter / receiver setup.

Hmm... I think I'll have to look into this some more. I really want a powerful coilgun that works well. Thanks for the info ;D