How I make helicopter rotors.....The hubs are automotive wire ends, just the female end, the rest I have no use for. I remove the plastic, hammer the round part flat and solder three onto an appropriate sized washer.
I use a piece of copper tube that comes with a solid insert ( available at a stained glass store). It's about 1/8" tubing. Now comes the hard part.....I drill a 1/8" hole in the helo, usually about 1" deep, insert the tube leaving about 1/8" showing. Next I solder the solid insert onto the washer....must be perpendicular! don't want wonky rotors!......by then I've made a bit of a mess so I file a bit and paint all the metal silver. Lastly I insert the blades, cut from hard wood, angled in the correct direction, crimping them in place.