[jdmilla]

It arcs while inverted. If I start level and upright and half roll to inverted it will start heading off course. I can correct with rudder. I can't tell exactly where it starts to deviate in the half loop, but I'm thinking its when the angle of attack goes from the bottom of the wing to the top of the wing. If I pull to vertical from level flight it tracks straight through the first 500', so I'm thinking its not a thrust issue. I have 2.3 deg right thrust. I didn't want to start adding washers until I was sure it was a thrust problem. All the surfaces seem to be centered, but I do have slightly more gear slop in the ailerons and elevators than I would like. I'm currently using PowerHD 9150's but am in the process of switching out to Hitec 7955TG's and aluminum arms. Rudder servo already has the Hitec. I'll try to check wing incidence along the wing span to see if there is a warp. I'll keep plugging away at this and all suggestions are welcome.