CONTENTS WHAT TO DO WHEN ..................1-3 SERVICE ACCESS FACE COVER ..................4 REAR COVER ................... 5 FRONT COVER ................. 6 MECHANICAL ADJUSTMENT TOP TENSION ................... 7 BOBBIN TENSION ................8 PRESSER BAR HEIGHT AND ALIGNMENT ........9 NEEDLE SWING ................10 NEEDLE DROP ................
MODEL 3128 WHAT TO DO WHEN CONDITION CAUSE HOW TO FIX REFERENCE 1. Skipping 1. Needle is not inserted Insert the needle properly. properly. stitches 2. Needle is bent or worn. Change the needle. 3. Incorrectly threaded. Rethread. 4. Needle or thread are...
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MODEL 3128 CONDITION CAUSE HOW TO FIX REFERENCE 3. Breaking 1. Initial sewing speed is Start with medium speed. upper too fast. thread 2. Thread path is incorrect. Use the proper thread path. 3. Needle is bent or dull. Replace with a new needle.
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MODEL 3128 CONDITION CAUSE HOW TO FIX REFERENCE 5. Needle 1. Needle is hitting the needle See mechanical adjustment P.11 breaks plate. “Needle drop.” 2. Needle is bent or worn. Change the needle. 3. Needle is hitting the hook See mechanical adjustment P.12, 13...
MODEL 3128 SERVICE ACCESS FACE COVER TO REMOVE 1. Remove the setscrew "A". 2. Take the face cover "B" off. Note: When removing the face cover, pull it up and unhook from the hook "C". TO ATTACH 3. Follow the above procedure in reverse.
MODEL 3128 SERVICE ACCESS REAR COVER REAR COVER TO REMOVE 1. Remove the face cover (see page 4). 2. Remove the setscrews "A", "B", "C", "D", "E" and rubber cushion "F" (2 pcs.), and then remove the rear cover. TO ATTACH...
MODEL 3128 SERVICE ACCESS FRONT COVER PATTERN SELCTOR DIAL TO REMOVE 1. Remove the face cover and rear cover (see pages 4, 5.) 2. Pull out the pattern selector dial. 3. Loosen the setscrews "A", "B" and remove the setscrews "C", "D" and the rubber cushion "E", then remove the front cover.
MODEL 3128 MECHANICAL ADJUSTMENT TOP TENSION TO CHECK: The standard upper thread tension should be 65 - 95g when pulling the thread (cotton thread #50) in the direction of "A" with setting the tension dial at "3". (Make sure the foot should be lowered.)
MODEL 3128 MECHANICAL ADJUSTMENT BOBBIN TENSION TO CHECK: Set the bobbin in the bobbin case and pass the thread (cotton #50) through the tension spring. The bobbin thread tension should be 45 - 55g when pulling the thread in the direction of "A".
MODEL 3128 MECHANICAL ADJUSTMENT PRESSER BAR HEIGHT AND ALIGNMENT TO CHECK: 1. Raise the presser foot lever. 2. The distance between the presser foot "C" and the needle plate "D" should be 6.0mm (0.24"). ADJUSTMENT PROCEDURE: 1. Remove the face cover (see page 4).
MODEL 3128 MECHANICAL ADJUSTMENT NEEDLE SWING TO CHECK: Adjust the needle swing according to the following procedure, if the needle bar starts moving sideways while the needle is in the fabric at sewing the zigzag pattern (with maximum zigzag width).
MODEL 3128 MECHANICAL ADJUSTMENT NEEDLE DROP TO CHECK: When the needle swings in maximum zigzag width, the distance between the both ends of needle hole in the needle plate and the needle drop positions should be equal. If not, make an adjustment as...
MODEL 3128 MECHANICAL ADJUSTMENT CLEARANCE BETWEEN NEEDLE AND HOOK (NO.1) TO CHECK: The clearance between needle and shuttle hook should be -0.05 - 0.10 mm. If not, make an adjustment as follows: ADJUSTMENT PROCEDURE: 1. Remove the face cover (see page 4).
MODEL 3128 MECHANICAL ADJUSTMENT CLEARANCE BETWEEN NEEDLE AND HOOK (NO.2) TO CHECK: Use this adjustment method No.2 if the clearance cannot be adjusted with the method No.1. The clearance between needle and shuttle hook should be -0.05 - 0.10 mm.
MODEL 3128 MECHANICAL ADJUSTMENT FEED DOG HEIGHT MACHINE SETTING 1. Stitch selector: " " 2. Needle bar: At its highest position. TO CHECK: 1. Lower the presser foot. 2. Turn the handwheel toward you until the needle bar comes to its highest position.
MODEL 3128 MECHANICAL ADJUSTMENT NEEDLE BAR HEIGHT MACHINE SETTING 1. Stitch selector: " ". TO CHECK: When the tip of shuttle hook meets the left side of the needle in ascending travel of the needle from its left and lowest position, the distance between the top of the needle eye and the tip of the shuttle hook should be in the range of 2.9 - 3.5 mm.
MODEL 3128 MECHANICAL ADJUSTMENT NEEDLE TIMING TO SHUTTLE MACHINE SETTING 1. Stitch selector: " ". TO CHECK: The height of the needle point from its lowest point of travel should be in the range of 1.45 - 1.95 mm when the tip of the shuttle hook just meets the left side of the needle at the left needle position.
MODEL 3128 MECHANICAL ADJUSTMENT BUTTONHOLE FEED BALANCE TO CHECK: When sewing buttonhole, the stitches on each side of buttonhole stitch density should be the same. The range of 9 - 11 stitches in the right side row "backward feeding" against 10 stitches in the left side row "forward feeding"...
MODEL 3128 MECHANICAL ADJUSTMENT ADJUSTMENT OF RIGHT HAND LINE TACK WIDTH AND CAM FOLLOWER RELEASE AMOUNT * The width of the left and right side line tack of buttonhole should be equal. If there is large difference between left and right line tack width, the cam follower may be hindered with the zigzag cam block when you turn the pattern selector dial.
MODEL 3128 MECHANICAL ADJUSTMENT MOTOR BELT TENSION TO CHECK: 1. Too tight or too loose motor belt tension may create belt noise and also too tight motor belt tension can cause the machine to run slow and will overload the motor.
MODEL 3128 OILING Factory lubricated parts will provide years of household sewing without routine oiling, but check rot possible lubrication needs whenever servicing machines. Use good quality sewing machine oil at the points "A", "B", "C", "D", "E" indicated by black arrows.
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