[recycled sixtie]

Way back in the 1970's I used to fly a Canso PBY5A. The ailerons were so big that if you made a left turn then the aircraft would turn to the right if you did not use left rudder. This is called aileron drag. To make a left turn you had to add left rudder to compensate for the aileron drag as well as inputting left aileron.

The amount of rudder you use depends a lot on the aircraft type and the circumstances you are in. The other extreme is a jet aircraft. To takeoff and land a jet you need to use some rudder in combination with the ailerons. Once the jet is in the air and cleaned up, you don't touch the rudder as it becomes way too sensitive.