A seej cannon I designed to launch pennies in volleys of either one, two, three or stacks. It didn't work as well as I hoped for a stack of pennies but works wonders in launching nerf darts. Features include trigger, variable power (easily attach additional rubber bands for mroe power) and angle adjustment.
The hammer rods fit in the hammer and the trigger cap. The hammer rod in the hammer is pulled by one end of the rubber bands and then other end of the rubber bands is held on by the pegs on the main cannon. The trigger also grabs onto the hammer rods to hold the hammer in place. The trigger cap is placed at the back of the main cannon to hold the trigger and prevent the hammer from falling out when no rubber bands are attached. Enjoy and be safe. 2-4 rubber bands should be sufficient in launching pennies a considerable distance and do not aim at eyes. Never look down the barrel if rubber bands are in place.