How accurate is the wing section profile near the blade root?
A. For wide chords near the blade root (first 20% of radius) the relative airflow will follow a significantly curved circular arc rather than a straight line from wing leading edge to trailing edge. The wing section plots should therefore ideally be curved in this same arc before being used to cut a wing segment which is clearly difficult with flat sheet polystyrene. A later version of the software is planned to compensate for this distortion so allowing flat sheet to be used all the way to the root. Both the drag and power contributions of this first 20% of blade are relatively small so in practice the current inaccuracy is not very significant.
