On this and a couple of other planes, I got the feeling that the tailplane was being pushed to its limits and the nose wasn't coming up enough. I've added tail weight with no results other than jumpiness.
I'll make the tail enough bigger to see if it helps. I can always cut it down if it's too big.
Downsizing planes to 15 size can end up with things like an undersize tail.
Hi Paul, what does your Akromaster weigh? I've had an Akromaster for a couple of decades.
It weighs 17.5 ozs and is a flying mini elephant. It also does wide radius 90 degree direction
turns. The answer is simple, the wing loading is too high. It is powered by a Chinese Yin Yan
plain bearing 5oz diesel engine. This same engine has flown a Dumas Tomahawk on 60' X .015"
lines which weighs the same 17.5 ozs. Yet, it fly's a much better stunt pattern. The reason is
the Akromaster has a 10.5 oz/sq' compared with the Tomahawk's 7.6 oz/sq' wing loading.
About seven years ago, I went a bit crazy and scratch built another Akromaster, shortening the nose moment for
the MP-Jet 1.0cc diesel engine and much smaller fuel tank required. It has a 6.65 oz/sq' wing loading and
pops square turns like a Combat ship. I changed nothing but the nose moment.
Tony