Section 15.2 gave the normal range of spur gear face widths as 9/P to 14/P, and Section 16.2 stated that it is usually desirable to make b ≥ 2.0 pa. Accordingly, it is desired to make a helical gear with face width equal to 13/P and also equal to 2.2pa. What helix angle is required to do this? How does this compare with the commonly used range of helix angles cited in Section 16.2? Refer to Figure P16.1.
