Specifics of building a multi-stage coilgun?
What I'm looking for now is some more detailed input on the exact power requirements, circuitry, etc.
Specifically: Firing a standard .177 steel BB, I want to use many small coils in series as opposed to one/few large ones. From my understanding, this will provide better end speed while keeping each coil's power draw relatively lower, and thus safer. (Am I right about this?) How many coils should I use, what would be overkill, etc?
Each coil will be triggered sequentially by a IR LED/photocell trigger system rigged through tiny holes drilled across the barrel. Will a simple on/off circuit suffice, or will the projectile pass by too quickly for the full charge to release? If so, I assume I need a system to trigger a full discharge when tripped. Correct or not, and if so, how?
I'm also considering fitting an extra gate at the end to trigger a circuit to bleed any remaining charge. Ideas on this?
What size of capacitors should I use, and how would I charge them? The only thing Google can seem to turn up is camera flash circuits, but I'd much rather have one tailor-built to the system's exact levels. I'm going to use a press/hold switch to charge them, and would like an automatic shutoff with an LED that comes on when they are charged, but turns off when I release the button. Kind of like a camera flash, actually.
I'd like to fit it with a re-chargeable battery. What sort of power is required here? How many firings would I likely get per charge, etc?
What sort of muzzle velocity can I expect? I don't want to kill bears with it, but soda cans would be nice. I don't want to waste my time fabricating it only to be able to stop it with my eyeball.
Lastly, are there any other points of concern or things I should know?
Thanks for any input, and if everything ends up coming together nicely, I'll be sure to properly document the process for everyone's enjoyment. :)