RE: V-Tail Incidence
I posted this about 5 years ago, but it is how the figure where the leading edge and trailing edge meet the fuselage when the wing is at zero-zero.
First, measure the width of the fuselage where the leading edge and trailing edge of the V-tail meets the fuselage. Subtract the TE width from the LE width and divide by two. I try to measure this to a 1/32" accuracy. Take the Tangent of the angle to horizontal (180 – {V-tail angle})/2. For example on a 120 degree V-tail, it’s 30 degrees. So working out the trailing edge position is : [(LE width– TE width)/2] x tan (30). This distance is the amount that the TE of the V-Tail is lower on the side of the fuselage than the LE for zero incidence. Place the fuselage with the wing mounted so that the leading and trailing edges are blocked up an equal amount (zero-zero) on the obligatory flat surface.
Now a fully race trimmed quickie has almost no control throw, and if you miss getting the tail incidence right, you can end up with an airplane that is nearly unflyable. However, if you move the CG forward from race trim, you can increase the control throw (50% to 100% more travel) and a slight error is easier to deal with.