First print out one of each top plate and four of the landing gear and motor mounts. I made the plates out of PLA and used 20%in fill. ABS 50% infill on the motor mounts. Use 8, M3x20 for the frame and M3x8mm bolts to attach the motors. I used 10 inch long arms and that worked really well but feel free to experiment.
The M3 bolts sit in the countersunk holes in the back of the motor mounts with a 7mm diameter M3 washer. Then the motor mounts get zip tied onto the arms. Make sure that the zip ties are TIGHT!!! or else you will get slippage. My quad weighs 900g with the 1/2 inch wood arms and 5 amp battery(AUW). I ordered all the parts from hobbyking and BuddyRc and all of the fasteners from amazon.