I made some further tests with the 0 downthrust, 5 wing incidence, 0 tailplane incidence plane. This is the one with the single hole prop bearing and the shim blocks at the leading edge of the wing and trailing edge of the tailplane. It was windy in the treetops with some swirling near the ground. I used an 11″ loop of 3/32″ with 1,318 turns capacity. I put in 400-450 turns to keep it out of the tree tops. It got up high enough to drift most of the way across the field. I forgot to oil the prop bearings, so I could hear it squeaking.
The wing was twisted like a potato chip from the last outing. I broke the joint between the spar and rib in the left aft corner where the tension line radiated and reglued the rib a bit closer to the center to relieve the tension. That got rid of the severe washout on the left tip. The wing went back to almost straight, but had a bit of washout on the right tip. I was able to twist that out, mostly. Sometimes it may be necessary to sand a bit off the end of the rib to relieve the tension.
I got flights of 20-30 seconds. The flights were irregular, but that may have been swirling wind. It wandered until I gave it a bit of left rudder, then it circled nicely. It came down a little steeply. CG was at 1/2″ behind leading edge. I suspect the wing could go further forward.
Circling back after launch.
The sun made it hard to follow the flights.
See the attached video.