An apparatus for depositing a radius filler, made of a homogeneous material, into a groove, formed in a workpiece and having a length, the apparatus comprising: a chassis, movable relative to the groove; first means for extruding the radius filler along an extrusion axis; a tool center point, associated with the first means; second means for providing the homogeneous material to the first means, wherein the second means is attached to the chassis and the first means is attached to the second means; third means for compacting the radius filler in the groove, wherein the third means is attached to the chassis; a first sensor, attached to the chassis and configured to provide first-sensor output, representative of first geometric characteristics of the groove along at least a portion of the length of the groove before the radius filler is deposited into at least the portion of the length of the groove; and a controller, operatively coupled to the first means, the second means, and the first sensor and wherein: based on the first-sensor output, the controller is configured to determine the first geometric characteristics of the groove and, based on the first geometric characteristics, the controller is configured to control second geometric characteristics of the radius filler, extruded by the first means, as the tool center point is moved relative to the groove, characterized in that the apparatus further comprises a second sensor, attached to the chassis and configured to provide second-sensor output, representative of third geometric characteristics of the radius filler in the groove along at least a portion of the length of the groove after the third means compacts the radius filler in the groove. a chassis, movable relative to the groove; first means for extruding the radius filler along an extrusion axis; a tool center point, associated with the first means; second means for providing the homogeneous material to the first means, wherein the second means is attached to the chassis and the first means is attached to the second means; third means for compacting the radius filler in the groove, wherein the third means is attached to the chassis; a first sensor, attached to the chassis and configured to provide first-sensor output, representative of first geometric characteristics of the groove along at least a portion of the length of the groove before the radius filler is deposited into at least the portion of the length of the groove; and a controller, operatively coupled to the first means, the second means, and the first sensor and wherein: based on the first-sensor output, the controller is configured to determine the first geometric characteristics of the groove and, based on the first geometric characteristics, the controller is configured to control second geometric characteristics of the radius filler, extruded by the first means, as the tool center point is moved relative to the groove, characterized in that the apparatus further comprises a second sensor, attached to the chassis and configured to provide second-sensor output, representative of third geometric characteristics of the radius filler in the groove along at least a portion of the length of the groove after the third means compacts the radius filler in the groove. based on the first-sensor output, the controller is configured to determine the first geometric characteristics of the groove and, based on the first geometric characteristics, the controller is configured to control second geometric characteristics of the radius filler, extruded by the first means, as the tool center point is moved relative to the groove, characterized in that the apparatus further comprises a second sensor, attached to the chassis and configured to provide second-sensor output, representative of third geometric characteristics of the radius filler in the groove along at least a portion of the length of the groove after the third means compacts the radius filler in the groove.