N2UMK

Thanks for the insight. Thinking about it more I might bevel the LE of the elevon starting at the top of the LE and cut back at the standard 45 degrees toward the bottom of the LE. Without that taper the elevon canot move downward. This will give me plenty of down (won't be used much!) When covering with one piece of covering the elevons are folded back over the top of the wing when the bottom covering is applied. Then held deflectd down when the top covering is applied. This is the typical installation for a "monokote" hinge. It seems that the CA hinges would have to go in at the top of the elevon (bent at 45 degrees at the center of the hinge) and the top of the trailing edge - also with the CA hinge bent down as it enters the TE of the wing.