The mechanical design is pretty simple. A battery box/motor mount will be made out of 3/4in aluminum box section braised together. Then a hexagon of 3/4in aluminum conduit will be braised together and used as the prop guard. I have chosen to use braised aluminum because it is cheap, light, and strong. Brazing is also easier then using brackets and mechanical fasteners. I have found these Hobart Braising Rods work very well. 

Here is the basic cad model

I still need to figure out straps/padding. My next log will be the finished V1 backpack.