Abstract: Apparatus for cutting vegetation with a rotating head carrying cutting line extended into a cutting plane. Additional line is extended into the cutting plane by pushing a ball member against the ground while rotating the head. The ball member moves inwardly for releasing a spool carrying coiled cutting line to rotate a predetermined angular displacement in the head. After the cutting line length is extended, the spool is secured automatically against further rotation within the head.A cover is releasably secured to the head by a twist-lock connection to allow the ball member and spool to be removed from the head for rewinding, etc. The ball member and spool are journaled within the head and cover for rotation about a common rotational axis with the head and each other. As a result, head balance and smooth rotation are maintained during repeated extensions of cutting line.