[Walt]

At 1/2+ throttle fly the plane straight at yourself at a safe distance with a no wind condition, preferably by yourself for obvious reasons. Concentrate on getting the wings dead on level coming towards you, its easy to see at this attitude. Easily pull the plane vertical at 1/2 throttle and watch the plane transition into the vertical climb. Adjust rudder trim for the plane to enter and establish the climb straight. when you get this down, go to full throttle and do it again. Usually if there's a trim issue that re appears it may indicate the need for more engine offset. It'll take time to dial this in but this was the way I was taught for the initial check and a starting point for rudder trim, it works. I have also found that if a plane is straight and your construction numbers are right there's usually no reason for a plane to require more than 2-1/2 degrees offset on the thrust line. I did mention usually BTW.....Prop's and CG changes will require you to start over again....