I believe I have found where the flutter is coming from. It's the ailerons. The guys at the field though the rudder had a lot of slop on the hinge. They suggested taking the monokote hinge off and replace it with mylar hinges. So I did that. Still had flutter with the new hinges. Then I put a 6 to 8in piece of cellorphane tape on the end of each aileron. Still had so flutter but the sound had changed. Then added another piece to the bottom. All the flutter then was gone. I could fly fast as I wanted and dive as hard I wanted with no flutter.