Number of rotors
Posted: February 25th, 2013, 11:27 am
Should we use 2 or four rotors on top?
First, I hope you meant blades, not rotors.
Depends.
Have you built a copter before? If not, stick with 2 counter rotating rotors, with 2 blades each till you can make that work. They are adequate to 2 minute plus flight times. That'll win most regionals, many states, and place respectably at nationals.
If you don't understand what I just said, don't even think about 4 blades, go find some SO helicopter videos on youtube and see that the event is about.
OK, you've mastered 2-bladed rotor copters. Can you build a 4 blade rotor to the same weight as a 2 blade one? If yes, try it.
Finally, at the same weight, and with optimized rubber for each , which flies longer. Go with the data, not an opinion from the web.
There is some theoretical reasoning that says more blades is better, but that's all irrelevant if you can't build and execute it properly. And 4 bladed rotors are MUCH harder to build to weight.
Jeff Anderson
Livonia, MI