Bowmen of Skelmersdale

Rods, weights and risers

The Table below shows the relative effects of adding different rods on rotation in different directions. Be careful when reading the table; the forward/backward rotation discussed is the rotation induced by the shot or the archer, NOT any rotation due to gravity. Gravity-induced rotation is chiefly due to balance.

Notice that the main effects of stabilisation are on rotation around the vertical axis.

That is mainly because the largest stabiliser in the system is the riser itself; it often weighs two or three times the total of all other weights and is about 20-26

long, with a lot of mass near the limb fittings. That makes it a very effective stabiliser

for all but rotation about its own long axis.

Stabilisers and Rotation

How big is each stabiliser’s effect on each rotation?

Remember that this table relates to the effect on rotation induced by torque. For the long rod, the effect on balance is large, but the rod adds relatively little to the moment of inertia about the lateral axis.

What bow behaviour needs controlling?

Bow  movement

Timing - When is movement important?

Time and Motion

Controlling bow displacement

Weight, Mass and Inertia

Static and Dynamic properties

The misnamed TFC

Controlling bow balance

Centre of Gravity

Finding the centre of gravity

Changing the balance using weight

Weights and Distances

Rods, weights and risers

Controlling bow vibration

Causes of Bow Vibration

Reducing Vibration - Damping

Bow Resonance

Tuned damping - more on TFC’s