How to adjust the bottom thread and top thread of upper sewing machine

Check whether the bottom thread is correct first, and then check whether the thread clamping spring and shuttle spring are properly adjusted. Whether the machine lubrication is normal. Whether the needle bar height is normal. Whether the position of hanging shuttle matches the height of needle bar. Whether the surfaces of hook and shuttle sleeve are smooth. If these problems have been eliminated, please check the distributor again. If there is no problem, it is the performance problem of the machine itself. If some woven fabrics are too thin or too thick, it is difficult to adjust the bottom line. Hebei Qingxian Shuangxing Sewing Equipment Co., Ltd. mainly produces: double-needle sewing machine, shoemaking sewing machine, luggage sewing machine, upper sewing machine, double-needle upper sewing machine, thick thread double-needle sewing machine, thick material double-needle sewing machine and so on.