Basically, the whole contraption pivots around the suspension wire. The operator rotates the pendulum a small amount, say 10 deg., and starts it oscillating. The period "T" of the oscillation is established and plugged into the moment of inertia formula. The formula used for a two wire pendulum is I=(M*g*T^2*b^2)/(4*pi^2*L), where I=moment of inertia, M = mass (kg), g = acceleration of gravity (9.81 m/sec^2), T = period of oscillation (sec), b = distance from suspension wire to center of gravity (m), L = length of suspension wires (m).
I believe, that since T^2 and M are the only variables in the equation, one could simply make that calculation and be able to directly compare different guns. Moment of Inertia, I, is an indication of the energy required to change the orientation of an object; so a low figure would indicate a "lively" gun. A high figure would indicate just the opposite.
Last edited by Carpetsahib; 08/18/12 11:16 PM.
