Hi,
Doing flaps is difficult whether it be our unit or any unit. Its best to have on a 3-position switch. To start put the switch in the center position. This equates to neutral on other surfaces. Get both your flaps equal. Its best to try to get the mechanical linkage as close as possible in this position to minimize the adjustments. Function 1 is servo A, function 2 is servo B. Once these are equal, do the full down or full up positions. Just use Incr and Decr to get the flaps into position.