A new method to optimise cam timing for a compound archery bow

Compound archery bows have an eccentric cam at the end of each bow limb. These cams are used to shape the bow’s force-draw characteristic. If the cams are not timed correctly, the archer will have arrows hit high or low on the target, depending on how firmly they pull into the bow when at full draw. The various commonly used methods to adjust cam timing are either indirect, imprecise or require elite archer expertise. This paper provides a new method that directly measures any rotation of the bow as the draw length is varied about the full draw position and is independent of the archer’s skill level. Only simple equipment is required.