Arrowhead Quad Copter FPV Frame
I wanted to make a frame that could house my 3300-4000mAh batteries. The arms can be 1/2" wood or aluminum; 8" long. (I went with wood)
I am using (and including) the motor brackets and smaller landing gear stls from http://www.thingiverse.com/thing:175726 as well as my main body. Use the measurement tool for marking where to drill the holes for your arms.
Also, I used M3 40mm screws for my copter.