How to make a DIY quadcopter propeller with 3d drawing pen

Matt Quest made a quadcopter with 3d drawing pen, now he will teach you how to make fully working propeller for it with same technique. He uses a regular propeller as a model and "draws" over it to make a copy. Then there is some postprocessing and sanding, but the propeller works. Regular replacements are not expensive, but it is useful thing to know.