Rodney

I have used boost tabs on many 1/4 scale craft. They are very helpful, lets a low torque servo do the job of a giant servo. do limit the area of the tab to 10% max of the moveable surface however. Every time I tried to use more, the surface would tend to oscillate near neutral position while still working correctly at any other deflection. Maybe oscillate is not the right term, but the plane would seem to hunt or wag when the surface was at neutral. They worked well on ailerons as well as rudder. I had best results when the tab always stayed lined up with the fixed surface no matter which way deflection went. On rudders, I have found that balance tabs (a part of the moveable surface forward of the hinge line) worked as well as the boost tab and was somewhat simpler to set up than the boost tabs. Again, 10% seemed to be the maximum area you wanted ahead of the hinge line when using balance tabs. One big advantage of the balance tabs, it gives both aerodynamic and static balance enhancement.