The inner cable machine must be lubricated with special sewing oil. After continuous use of the internal line machine, oil should be added once. If you use oiling in between, you should let the machine idle for a period of time to allow the oil to fully penetrate and pour the excess oil, and then clean the nose and table with a clean soft cloth to avoid staining the sewing material. Then thread and sew the rag, use the sewing thread movement to wipe off the excess oil stains until there are no oil stains on the rag, and then proceed to formal sewing. The refueling parts of the internal machine are as follows:
(1) The oil hole in the head of the inner cable machine, lubricate the upper shaft and the parts connected with the upper shaft.
(2) The components in the panel and the moving parts connected to each part. Lubricate the foot bar and needle bar and their connecting parts.
(3) Wipe the moving part of the lower part of the machine board and add less oil.

Reasons for the disconnection of the internal machine and its treatment
1. The needle is not installed correctly, so the needle should be reinstalled so that the needle groove is correct for the operator.
2. The threading method is incorrect, and the thread should be re-threaded according to the line drawing.
3. The needle eye and needle groove are not smooth, replace the needle with a new machine
4. The quality of sewing is not good, so we should switch to better stitches.
5. Sewing is thicker than sewing, use medium machine needles or stitches instead
6. The sewing tension is too large and should be adjusted appropriately.
7. The machine needle is not properly matched with the bending needle and the bandage needle, and adjust according to the matching standard of the machine needle, the bending needle and the bandage needle.
8. Machine needles, loopers, needle plates, presser foot tongues, threaded holes, etc. have burrs or scratches. Use oilstone or fine sandpaper to re-grind, or replace scraped mechanical parts.