Hello guys,
really nice explaination majortom!
As the experts suggest, those mixes should remain ON all the time. Actually, they correct a bad behaviour of the airplane: with them you can reach a almost ideal airplane behaviour - i.e. with rudder input only yaw will be produced, no pitch, no roll. One important thing I learned here on RCU from the great Don Sczcur, is that those mixes are important not only on pure KE flight, but they are needed during almost all the aerobatic manouver. When you have them correctly setup, try to do a slow roll, for example: you will be astonished how simple now it is to perform!!! Also rolling harriers are much more easy, always for the same reason - you give rudder, the plane yaw and doesn't do other bad behaviours.
Majortom said you a very important and not obvious thing, that I learned after many airplane setups
The mixes are quite speed dependand. This means that you have to concentrate on throttle setting during KE and in general try to fly aerobatics with the same speed. This is not a simple thing - one of the most difficult skill to achieve, in my opinion (I'm still learning it
Last thought, as majortom pointed out, is that an aerobatic plane should be trimmed to fly straight following some process, and the mixes are at the end of it. This means that there are other things to setup before, so if you have them "off" you can have hard time to mix the plane! Most important are CG and thrust angles, IMHO. If you are interested, just ask, there are some good infors on the net, fortunately
What plane do you fly?