04-08-2020, 12:40 PM
Hi guy`s..... personally,I think Marcel has got it in one!! From what I have observed lately at the field, insufficient emphasis is placed on the COG location. When you consider that we are talking about small percentages of the chord, approximations are rarely good enough. Test equipment should be used to get the best results . If it is considered that air is alway`s in a horizontal stream, which it is not, then the angle of attack of the wing, relative to the air stream can be best visualised. The greater the angle the more lift, till it reaches a point of maximum lift...then it starts to act as an air brake . Similarly, if the model is tail heavy then adverse control can be expected due to the tail down attitude, increasing the angle of attack.....Nose heavy, and the model will want to nose dive.....It could be a worthwhile investment for the club to purchase a test rig to prove one way or another if the set up is absolutely correct. It could improve members confidence and increase participation. These items are not expensive for the accuracy they provide.