1. The head rotates slowly

Analysis: Adding the wrong lubricant, especially the vegetable oil; too much dirt in the shuttle; the connecting rod screw, the conical screw is too tight

Treatment method: After rinsing with kerosene, refill the sewing machine oil; clean the shuttle bed; loosen the screws to ensure the gap.

2. When sending, half a circle is sluggish, half a circle is slippery or there is a stagnation point per revolution.

Analysis: The internal thread of the shuttle bed is not only half-stagped and accompanied by severe vibration and noise during operation; the position of the feed dog is high or the dirt accumulates in the tooth gap, so that the feed dog touches the needle plate when it rises.

Treatment: Clean the shuttle bed and add a little sewing machine oil; clean or lower the feed dog; replace or straighten the needle bar.

3. The machine head is stuck and cannot move

Analysis: The position of the feed dog is too far forward or too far back, and the needle plate is touched; the needle bar is installed too high, and the needle clamps against the casing.

Treatment method: adjust the position of the fee