1. Appearance inspection: Check whether the outer surface of the sewing machine is damaged, uneven or scratched by visual inspection and hand touch, whether the decorative patterns and handwriting are clear and firm, and whether the machine shape and color are beautiful and generous. .

2. Inspection of trademarks: Check whether the trademark has any traces of forgery in terms of color, pattern, handwriting, workmanship, etc. In addition, check the random quality certificate to see its quality level, whether it is stamped and the date of manufacture, etc.

3. Different seals: According to industry standards, defective sewing machines should have a second-class or third-class seal on the trademark and certificate. The parts are irregular and the interchange rate of machine parts of the same brand is low.

Extended information:

Notes:

1. The machine must be placed smoothly. The rotary hook structure is the main factor affecting the noise and vibration of modern sewing machines. The key is that the screws must be tightened firmly when installing the machine, and the screws on the tabletop must be screwed deeper so that the surface is not exposed.

2. When using the machine, do not put all the weight of the person on the table to prevent the table from deforming.

3. When the sewing machine is idle, put a layer of cloth on the presser foot, and cover the machine head with a piece of cloth to prevent dust, moisture, and sun.

4. When sewing thick parts, the presser foot needs to be raised (half-lifted), otherwise the needle and thread may break.

5. Remove dirt from the machine head. Do not use toothpicks, needles and other sharp objects to avoid damaging parts.

Baidu Encyclopedia-Sewing Machine