How to repair the broken thread of thick material of electric sewing locomotive

How to repair the broken thread of thick material on the electric sewing locomotive? (Why does the double needle sewing machine always break the thread? What should I do)

1·Confirm the thickness of the needle and whether there is any problem, whether the sewing thread is not strong, and whether it matches the thickness of the needle.
2·Adjust the tightness of the line reasonably.
3·If the sewing material is very thick and the sewing speed is fast, it is necessary to add silicone oil to the thread.

4·If there is any problem with the hook, check whether the hook tip is damaged.
5·If there is no problem with the above, it is necessary to adjust the fit between the needle and the hook according to the fabric to be sewn.

How do old sewing machines reverse stitches? It is a butterfly brand sewing machine. How should the old-fashioned sewing machine be sewn? Every time I use scissors, I leave a bunch of thread, which is short and loose. I heard that the reverse needle can solve the problem. How can I reverse the needle? every sewing machine

If it is the kind of foot, if you want to hit the needle, you must master the sewing machine. When the needle is hit, control the speed on the foot. Lightly lift the presser foot with the right hand and the left hand can move the fabric to do a reciprocating motion to achieve reinforcement. Note that the presser foot is raised too high, and it is easy to jump the thread.