Sethhunter

Martin I think you're right, and Don - I agree! But as Johny Depp said in Pirates of the Carib - It's really more of a guideline. Well, I look at it this way. First, where is the scale pivot and can I make it work. I'll move it if I think the benefits outweigh the asthetics, which I did here. Then there are the inertial loads (represented by weight times the g load) which can be very significant during maneuvers. I worry about this the most, because the loading will tend to pull the stab in a direction opposite to where you're trying to go (a.k.a. "the pullout aint happening!"). So pivot location (compared to the stab CG) and overall weight are important. Lastly the aerodynamic loads - static and transient. On a stab, I worry the least about the static aerodynamic loads, like neutral point (or point where the moment coefficient is zero). Although a flying stab is much bigger than an elevator, throw is less (I base the throw on the ratio of areas) and so the net lift is about the same and should be within the range of a servo that drives a comparably effective front-hinged elevator. Then there's the transient aero loads ( that cause flutter). In the venacular, blunt airfoils shed a Karman vortex that oscillates between the top and bottom side at a frequency that's about 20% of the ratio of air speed (say feet per second) to chord (feet), which gives you the units of hertz (cycles per second), for low Reynolds numbers. In this case, that's down in the tens of hertz. Hence a good stiff structure is important too. [reference, strouhal number].