The machine has a feed path (1) on which the timber is fed longitudinally to be contacted by four trimmers (7) The latter are mounted at right angles to each other in a plane perpendicular to the feed path. Each trimmer can move on a linear guide (9) toward and away from the wood for individual adjustment. The trimmers are controlled by upstream sensors (14) which detect the position of the wood to control the amount of rounding of the edges of the work by the trimmers.
