This is my first time here and I would like to request a simulation of the dynamics of a bow ([i]archery[/i]) ‘stabiliser’ for a power-point presentation I'm doing as a coaching aid for archers. I would like to treat the motion of the bow and stabiliser as a spring pendulum type motion being viewed from above.

            The bows centre of mass is moved laterally from the equilibrium aiming position by forced vibrations ([i]of 1/10 up to 10 Hz – the 10 Hz vibration may be superposed on the lower frequency[/i]) that originate at the shoulder. Rotatory inertia forces the bow to then rotate freely in the hand ([i]it's very lightly frictionally damped[/i]). The restoring force for the rotatory component of the motion is a vector component of the bows draw-force that acts to pull the bow in line with the line of force. Overall, this rotatory component of the motion due to inertia and string tension supposedly helps to reduce shooting error by keeping the angle that the bow is pointing away from the target centre at a lesser angle than the angle the line of force is away from the equilibrium position.

Oscillation is initiated by a rather large motion to bring the bow to the equilibrium (aiming) position where it is then halted abruptly. A low frequency arm “wobble” (< 1 Hz) and muscular tremors (~10 Hz) occur soon thereafter - the intent of the stabilisers is to reduce error due to these motions.

Even with sketches the detailed motion is difficult to describe for all circumstances and a Java simulation would be most educative and informative. Some sketches are shown in the attachment.