I am looking for a way to find the correct blade angle on an autogyro I am building. There is never enough wind to get a good feel for how the blades will spool up and the kind of lift they will produce. I have thought about using a convertible, but that has proven to be difficult. The blades are my own design and have a symmetrical airfoil. Are there any standards to start with? Does -2 to -4 degrees sound right?

Thanks for the input