Motor/propeller selection for quadcopter
We are a team of engineering students that want to get started in the world of multirotors. Our objective is to build a long endurance/high payload quadcopter for industrial applications, and we plan to innovate in the power system area.
So, without further ado here's our first problem. I've searched the internet for a while now and I've struggled to find information on how to choose an appropiate motor-propeller combination. I know the total maximun thrust should be a bit more than two times the the total weight but motor and propeller manufacturers rarely list the "thrust per rpm" of their props. Our initial estimation for the quadcopter's total weight is 3,3 kg. considering 200 g for each motor.
I did manage to find this static thrust calculator but I have no idea how reliable it is since it doesn't say how the thrust is calculated. (http://personal.osi.hu/fuzesisz/strc_eng/index.htm)
So that's about it. Any help would be greatly apreciated, no matter how small. It can be advice, information sources, or even builds that are similar to what we want to make and have already been tested.
Thank you very much for your time!
PS: Excuse me if my english sounds a bit weird, it just isn't my native language.