Here are some pictures of my 555 timer flyback driver with two of my flybacks. Unfortunately, I didn't have the parts to build a ZVS flyback driver, so I decided to improve my existing driver. The setup us simple, a 555 timer oscillates at a frequency determined by a variable resistor, and turns on and off a MOSFET that I found inside of an old computer power supply. The MOSFET is supplied with about 20 volts from two old lead acid batteries from an electric scooter. The arcs are quite impressive, especially for a 555 timer driver. I can draw sparks that are almost two inches long!
Sorry, no pictures of the driver yet, or of the longer sparks.