Quadrotor / Quadcopter airframe (small version)
by TheCase, published
a simple frame body for a small quadrotor, designed around ~1/2" square towel bar and the KK flight control board.
You should be able to print and fly in the same day!
the towel bar I used is about 16mm wide - I included the OpenSCAD source so you can tweak it to your needs.
Hardware is #6-32 nuts and flathead bolts for arms/frame and #4-40 for the control board. Use velcro straps in the slots to secure the battery.