Originally Posted by Lil Stinkpot
Waz, I moved he battery and camera forward a bit more, and (barring surprises on review) that seems to have cured it. ;-) I got distracted, and didn't try a dive test. I wanted to know why there were three whirlybirds hovering over my neighborhood more than I did if I got the CG perfect yet.
The Radian is really bad at the dive test, due to its flexible fuselage aft of the wing. Mine had a fairly neutral dive test until I stiffened the tail section with some 12K carbon tows (three each top, bottom, and both sides). After that, dive test resulted in a pretty significant pull up without any balance or trim change, due to the much stiffer tail section. I moved the CG back and I'm happier with it now. The carbon reinforcement also made a significant improvement in tail twisting.