There are 8 combinations of normal or reverse aileron, normal or reverse elevator and switching which servo is in which channel. One of those 8 will work correctly.
There are 8 combinations of normal or reverse aileron, normal or reverse elevator and switching which servo is in which channel. One of those 8 will work correctly.
Yes, the elevator and aileron channels can be reversed independently.
The reversal will effect both servos. One combination will give you the correct results.
You need to systematically go through the combinations until it works.
U16D
Just remember there is no elevator and aileron in an elevon set up. Either servo could do either but as Merv points out only one combination of receiver channel position and servo reverse will give the right result.
typically your going to need to have the elevator input to the mix reversed for one of the elevons and not the other, and no reverse for both ailerons (or both reversed)
you would do that in the mixing tab.
you should be able to find someone that will show you screen by screen how to set it up here (I don't have time to check them to give a specific recommendation)