The jig is made from 2X4 and MDF. First I determined the diameter of the front and rear of the finished cannon and the overall length I wanted. I then drew the profile out on a sheet of MDF and cut the profile out with a jigsaw.
Then I split the profile in half to attatch to the sides of the jig. This profile would provide the template I would use to carve out the material.
A piece of 1.5 inch Schedule 40 PVC is used to lay up the layers of foam and will also act as the barrel.