Jumper
(1) The threading method is incorrect. Rethread the thread according to the threading diagram.
(2) The straight needle is not installed correctly. Check the height and facing position of the needle, and make the needle move down slightly in front of the needle plate hole.
(3) The needle tip of the straight needle is hairy or bent, and the needle is replaced with a new one.
(4) If the tip of the looper needle becomes blunt, use oilstone or fine sandpaper to polish it, or replace it with a new looper.
(5) The suture tension is too large or too small, adjust the suture tension appropriately.
(6) The looper cannot cover the loop of the straight needle on the right, and the right stitch of the lower decorative thread is skipped. The loop of the straight needle is too small, so increase the amount of jumper appropriately.
(7) The looper cannot cover the loop of the left straight needle, the left stitch of the lower decorative thread, and the loop of the straight needle is too large, reduce the amount of jumper appropriately.
(8) The curved needle cannot hook the middle and left straight stitch loops at the same time, and the middle and left stitches of the lower decorative thread are skipped, and the amount of skipping is appropriately reduced.
(9) The middle and left needle thread on the back of the looper cannot pass into the triangle of the knitting needle thread and looper thread. The middle of the back of the left stitch skips stitches. Check whether the suture passes through the thread clamp. Check the synchronization of the bottom thread cam. If there is a problem Re-adjust according to the standard.
(10) The needle and the looper are not matched properly. Check the height of the needle bar and the synchronization between the needle and the looper. If there is any problem, readjust it according to the standard.
(11) The needle and the needle guard are not matched properly. Check the position of the needle and the needle guard.
(12) Improper matching of the machine needle and the stretcher needle or the wrong position of the stretcher needle, causing the upper decorative thread to skip stitches, check the matching size of the machine needle and the stretcher needle, and check the thread out of the stretcher thread.
Disconnected
(1) The threading method is incorrect. Rethread the thread according to the threading diagram.
(2) The needle is incorrectly installed. Reinstall the needle so that the needle groove faces the operator.
(3) The needle eye and needle groove of the needle are not smooth, so replace the needle with a new one.
(4) The suture tension is too high, adjust the suture tension appropriately.
(5) The quality of the sutures is too poor, so use better sutures.
(6) The suture is thicker than the eye of the needle. Use a moderate suture or needle.
(7) There are burrs or scratches in the thread holes such as the machine needle, looper, needle plate, presser tongue, thread hole, etc., re-grind with oilstone or fine sandpaper, or replace the scratched parts.
(8) The machine needle is not properly matched with the curved needle and the stretched needle. Re-adjust according to the matching standard of the machine needle, the curved needle and the stretched needle.
Broken needle
(1) The pressure of the presser foot is too small, and the needle is broken due to poor feeding. Increase the pressure of the presser foot to make the feeding normal.
(2) When the curved needle and the straight needle collide, adjust the matching position of the curved needle and the straight needle according to the standard.
(3) When the stretched needle collides with the straight needle, adjust the coordinate position of the stretched needle and the straight needle according to the standard.
(4) The straight needle and the needle guard are not matched properly. Adjust the match between the needle and the needle guard according to the standard.
(5) The tip of the curved needle is round and bald, and the curved needle should be replaced with a new one.
(6) The needle bar and the needle bar sleeve are worn too much, which makes the needle bar and the needle bar sleeve loose. Replace the needle bar and the needle bar sleeve.
(7) The needle hole on the needle board is too small, update the large needle board or replace the small needle.
(8) The mechanical parts are loose. Check the coordination and wear of the various parts of the hooking mechanism, adjust the size according to the standard, and replace the severely worn parts.
Flower needle
(1) The straight machine needle is too low to make the straight machine needle loop too large, so that the loops are intertwined with each other, and reposition according to the straight machine needle height positioning standard.
(2) The tongue of the needle plate is too narrow, which makes the straight needle loops easy to assemble, so replace the needle plate with a new one.
(3) The bottom of the looper is too narrow and round, and it is easy to prevent the straight needle loops from being separated on the looper, so that the loops are intertwined to produce a needle. Replace the looper with a new one.
(4) The straight needle and the curved needle do not fit well. Adjust the matching position of the needle and curved needle according to the standard.
Sewing material wrinkles
(1) The differential feeding ratio is improper, and the differential feeding ratio should be adjusted appropriately.
(2) The height of the feed dog, the front and rear position is improper, readjust the height, front and rear position of the feed dog according to the standard.
(3) Suture tension is too large, adjust the suture tension appropriately.
(4) The presser foot pressure is too large or too small, adjust the presser foot pressure appropriately.
(5) The small presser foot loses its up and down movement, and stitches or rust are embedded between the large and small presser feet, remove foreign objects between the large and small presser feet, remove the rust or replace the rusty presser foot.
Bad stitches
(1) The thickness of the thread is different, so use a better suture instead.
(2) The thread gripper is not working properly, remove the dust in the thread gripper to make the thread pass smoothly.
(3) The thread guide is not positioned correctly, adjust the tension of the needle thread, looper thread, and stretch needle thread.
(4) The cable hole is not smooth, and the cable hole is polished or polished.