l Now remove the vibrating presser bar connecting link (figure 4-7 [N]) from the face of the machine. . Loosen the presser-lifting link crank pinch screw (figure 4-11 [B]). Rotate the presser-lifting rockshaft (figure 4-11 [M]) away from the machine about 90 degrees. Remove the presser- lifting bell crank connection from its stud. Now remove the presser-lifting rockshaft; then remove the presser-lifting link crank (figure 4-11 [P]) from its connection link. Needlebar Rock Frame Position Bracket The needlebar rock frame position bracket (figure 4-7 [H]) holds the needlebar rock frame in position and prevents any side-to-side play. To remove the needlebar rock frame position bracket, you remove the holding screw and withdraw the bracket from the machine. Tension Release Rod The tension release lever rod releases the tension on the thread. This allows the thread to be pulled freely when you remove material from the machine. When the presser bar is lifted, the shoulder on the arm of the presser bar lifting releasing slide bracket presses the tension release rod, thereby releasing the tension on the thread. You remove the tension release rod by tilting the machine backward and allowing the rod to slide from its recess. Unscrew and remove the vibrating presser foot tension spring adjustment thumb- screw (figure 4-11 [Q]). At this point, you can remove the vibrating presser foot (figure 4-11 [R]). Vibrating Presser Foot The vibrating presser foot is the foremost foot. It moves fore and aft as well as up and down, and combines its actions with that of the needle and the feed dogs. Needlebar Rock Frame Hinge Stud The needlebar rock frame hinge stud (figure 4-7 [I]) acts as a hinging point for the needlebar rock frame. To remove the needlebar rock frame hinge stud, you loosen the setscrew on the top of the machine head; then you press the hinge stud out through the face of the machine. Needlebar Rock Frame Assembly The needlebar rock frame assembly (figure 4-7 [O]) consists of seven major parts: the needlebar connecting stud, the needlebar, the needlebar rock frame, the needlebar rock frame slide block, the vibrating presser bar, the vibrating presser bar spring, and the presser bar spring guide rod. To remove the needlebar rock frame assembly, you grasp it and withdraw it from the face of the machine. Needlebar Connecting Link Oil Guard The needlebar connecting link oil guard (figure 4-11 [J]) prevents oil from being thrown through the thread take-up lever groove. To remove the needlebar connecting link oil guard, you insert the screwdriver in the opening in the rear of the machine face, remove the holding screw and then remove the oil guard. Take-up Lever Hinge Stud The take-up lever hinge stud acts as a hinging point for the thread take-up lever. To remove the take-up lever hinge stud, first you loosen the setscrew located three-fourths of an inch to the right of the thread take-up lever; then you insert the screwdriver in the oil hole and push the take- up lever hinge stud out through the face of the machine. Thread Take-up Lever The thread take-up lever pulls the slack out of the needle thread to lock the stitch in the goods being sewn. To remove the thread take-up lever, you turn the balance wheel until the needlebar connecting link is at its lowest position; then withdraw the thread take-up lever through the face of the machine. Thread Take-up Lever Driving Stud The thread take-up lever driving stud transfers power and motion from the needlebar connecting link to the thread take-up lever. The thread take-up lever driving stud is attached to the thread take-up lever; they are removed from the machine at the same time. Needlebar Connecting Link The needlebar connecting link (figure 4-7 [J]) changes the rotary motion of the needlebar crank 4-23