Spiral Definition

Sine Half Wave (Japanese Sine)

This spiral definition is also known as Japanese Sine or Sine Half-Wavelength Diminishing Tangent Curve.

y = \frac{x^{2}}{4 R} - \frac{X^{2}}{2 π^{2} R} (1 - \cos \frac{π}{X} x)

Where

x	distance along the x-axis, the tangent (m);
y	offset distance from the x-axis (m);
X	length of transition curve along the tangent, the x-axis (m);
R	curve radius of the circular curve within the full body of the curve (m).

Czech Cubic Parabola Definition

l_{0} = l_{p} + t g^{2} λ \frac{l_{p}}{10}

Unlike in other spiral definitions, the user input spiral length in Czech Cubic Parabola definition refers to the tangent length. When user inputs a value of 10m this value should interpreted as tangent length of spiral and not the element length. You can see this in the drawing above.