Rotary positioning fence

A rotating fence for locating boards, comprising:

• a length of continuous track loop operable in a first direction of flow along its length and configured to convey one or more board stop guides in said first direction;
• a lateral structure generally disposed in a plane generally parallel to the first direction of flow, and including:
• a lateral positioning guide extending across at least a portion of the lateral structure at an angle oblique to the first direction of flow,
• a plurality of longitudinal guides extending from the lateral positioning guide generally in the direction of flow, the longitudinal guides being spaced at intervals along at least a portion of the length of the lateral positioning guide, and
• a guide selector positioned at one or more of said intervals, the guide selector movable from a first position wherein the longitudinal guide at said interval is blocked to a second position wherein the lateral positioning guide is blocked;
• and
• a board stop assembly comprising a board stop and a cam follower, the cam follower being configured to selectively engage the lateral positioning guide and said longitudinal guides.