For the chain stitch machine, there is always the problem of skipped stitches. The author believes that it is caused by a problem in the synchronization relationship between the needle and the looper.
According to the author’s actual experience, it is recommended to re-adjust the synchronization relationship between the needle and the looper according to the following standard requirements.
Needle bar height adjustment
Standard position: When the straight needle is at the bottom dead center position and the looper is at the rightmost position, the distance between the tip of the looper and the center line of the rightmost straight needle (short needle) is 3.5mm～5mm, loosen the clamp screw of the looper holder You can make adjustments.
In actual debugging, we only need to grasp that when the needle rises and the looper hooks the thread, the needle hole and the looper hole can overlap when they meet; when the needle falls and the looper retreats, the needle hole and the looper hole meet again If they still overlap, the cooperation relationship is correct.

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