RE: Rudder Coupling Causes & Fixes
While on knife edge, the model tends to tuck towards it's belly. (Up elevator is required to keep the model moving straight) I have a UCD3D that does pretty much the same thing and could only be fixed by mixing it out. Obviously, this tail design is not very effect for knife edges. Based on some of the responses, it would appear that extending the rudder futher below the stablizer would help alleviate this problem....
The model in question is the Mad 3D Taco which you can see on our website at [link=http://www.flyingthingz.com]www.flyingthingz.com[/link] I have attached the picture here for your reference as well.