wing tip plates
Had tip plates on my wanderer and they improved low-speed control quite a bit. My buddy had the same model without 'em and said there was a major difference. I had good control while landing, and never could tip stall that bird. I liked them so much that I added some to my SST .40, and as many of my non-scale birds as possible. I start at the leading edge and gradually open away from the wing surface until I have 3/4"-1" wall on top and 1/2-3/4" on the bottom. I also pull the upper TE of the plate slightly past the TE of the wing. The wing 'thinks' it's longer because low-pressure flow is kept on the airfoil, while the plate acts as a fence keeping high-presure bypass airflow from being drawn over the wing surface, destroying tip lift.