RE: Predator Misalignment
It helps to have a ROBART incidence tool, but you can check for flyability with a ruler, a triangle and string. The firewall should be perpendicular to the bottom of the fuselage, set the fuselage flat on a table and check this. Bolting a flat plate where the prop goes makes a handy reference to check squareness at. With a high wing plane, any up thrust at all is a bad thing, and with any plane, any left thrust is bad too, always err on the side of having down and right, but try for zero-zero on this plane.. With the wing mounted, measure the distance to the table from the wings' leading edge and trailing edge, these measurements should be the same all the way around. This check will reveal your wings' incidence and if the wing is twisted or not. Should be sitting at zero-zero now. The veetail can be checked with the triangle and ruler using the table top as a reference. It is easier for you to just dive in and do it, than it is for me to explain. The non stretchable string is handy to check how squarely the wing sits in the top view. I use a pin that is pushed in as far back on the fuselage, top dead center, then tie the string to it. The other end of the string is stretched out to both wing tips, the measurement should be within a 1/16". Finally, inflight trim adjustments will reveal slight problems with the veetail. Check your planes' lateral CG, a finger on the prop nut, and the other on the tip of the aft end of the fuselage will reveal a gross imbalance, [ can't figure why a foam winged plane could be too far out here]. Good luck!