TABLE 1.

Spring type, stiffness and force.

	Type	Stiffness	Force
Linear	Full [1]	250	250 Z
	Half [4]	125	125 Z
Non-Linear	Quadratic [2]	2083 Z	2083 Z2
	Logarithmic [3]	86.6 Z–1/2	86.6 Z1/2

The four different forces are rendered by changing the spring stiffness.