This is a quad copter I built. The body, arduino mount, and motor mounts are all printable.

Upper body was a derivitive of http://www.thingiverse.com/thing:24638 as I needed to adapt an arduino base to my upper body mount.

I have marked this as a work in progress as I tweak the designs, but the current version should be good to go flying! :)

The motors, props, etcs, and arduino shield was purchased from aeroquad.com. The frame is standard 3/4" square tubing from Home Depot and are cut at 6" lengths. The radio and battery came from eBay.

I used 10-32 bolts and nuts to assemble and M3 nuts/bolts for mounting the motors to the motor mounts.

The final picture shown here has laser cut acrilic for the landing gears. These eventualy broke during hard landings so I'm working on a printable landing gear. YMMV.