This quadcopter is designed to be lightweight. It uses 16 mm carbon fibre tubes as motor arms. All other parts of the frame are 3D printed. I printed the parts in PLA, but maybe PETG or ABS is a better choice to make it more crash resistant. The motor cables are routed inside the carbon fibre tubes, making the quad look really clean. The quad uses 6 inch propellers and is slightly larger than a standard race-quad. The total flying weight is 630 grams and is has a flight time of about 7 minutes while cruising around at a comfortable pace. Using a 3 cell 2200mAh battery.
The tubes are 16 mm outer diameter, 14 mm inner diameter and 330 mm long. I bought 2 of those and cut them in half to create four 165 mm long motor arms. The 3D printed parts are made to fit any tube with a 16 mm outer diameter. The motor mounts are firstly glued using CA glue to the carbon fibre tubes, then the tubes are glued to the base plate. The camera mount and rear mounting plate are screwed together using short M3 screws and nuts. The top plate is held in place using four 3D printed spacers. The holes in the spacers are slightly smaller than 3 mm, making it possible to thread M3 screws directly into the plastic.