KurtS

Interesting idea. I haven't sealed the gaps on the control surfaces of this airplane, I'll give it a try.

I have made some progress however. I reduced the down thrust of the engine a little and flew it again a couple days ago. That change had a positive effect in that less up elevator trim was needed and that I feel helped it fly inverted with probaly half the down elevator input that it required before, not to mention it maintained altitude with less up elevator trim. It still rolls off in a loop though but only if it is a tight loop. Again, the less up elevator input the less it wants to roll.

I also dropped $43 today on a Robart Incidence Meter (finally). It was hard to go down the trim chart from top to bottom when I didn't have to tool to properly check wing and tail incidence. I've now leveled the fuselage and checked that angles and while the horizontal stab was 0 degrees to the fuselage the wing was about -.5 degrees. I'd read that a fully symmetrical airfoil wing should be +1 degree compared to the tail and so a little tweaking and adjusting has it now at +.75 degrees - not perfect but much better. I think I posted originally that the model seemed to fly tail low and required 1/8" of up elevator to maintain altitude. Certainly the wt shift aft helped that a bit as did the reduction in down thrust. I think this wing incidence change should provide the greatest effect since with the wing set at a positive angle now the fuselage should fly level. As it was before, the tail had to fly the fuselage in a tail-low attitude in order to get the wing at the proper angle of attack.

I need to go test fly this latest change, hopefully tomorrow.

Kurt