I am planning to build a small (length about 15 cm) portable coil gun. There are some really good intructables out there. (I still don't have enough knowledge of how to build this thing) I found this site to be pretty interesting. http://www.jeffhove.com/robots/coilgunhowto.html How can I make a powerful coil gun like that with capacitors (not that whole blob of camera stuff)? I am hoping that it could be rechargeable, perhaps by a USB connector (5V). But that would not last long right? So I guess by adding some batteries would help. Trying to get this coil gun to the smallest size with a powerful blow. By the way, there is something called EMF that affects the system?