RE: Lanier U-2
I've made 3 of these with .15's on the nose. I know folks that use .049's and speed 400's. Takes off about 5 mph, wings start flapping at 15.
I normally cut the nose off 1" in front of the cowel, sink a 2 or 4 ouncer into the nose and glue on a piece of ply for a motor mount and landing gear attachment. Not sure how the electric guys do it, but its not much different with the battery around the balance point on the wing. Either cut the elevator and rudder out or just attach to the existing area, inch wide surfaces work fine. I forget who used to offer this airplane as the gooney bird or something like that, but it was the Lanier glider with the above modifications.
Oh yeah, 3 strips of 1 inch strapping tape on the bottom of the wing.