For Halloween my son wanted to be a Zombie Hunter. I couldn't let him go without a good weapon, all Zombie hunters need a good weapon. so I built him a mini-gun. This is a picture of him, and how we did it.
Using an Old Drill, We took two training wheels drill eight holes in each. Then cut a copper pipe into 8 equal sections about 16", and 1 section of pipe at 10" .Through the center I ran a threaded rod sleeved with the 10" pipe between the two wheels. The rod was cut long enough, 19", to extend past the wheel and get clamped into the chuck on the drill. I had to rebuild after installing the threaded rod to add washers on each side of the training wheels.