How to solve the problem of increasing noise in the sewing machine

The sewing machine is composed of various transmission mechanisms to realize the up and down movement of the needle rod, the elliptical trajectory movement of the cloth teeth, the rotation of the shuttle, or the swing of the shuttle. All movements have motion gaps, and these motion gaps cause parts to smrash and make noises during the operation of the sewing machine. The larger the gap, the louder the noise, the faster the speed, and the louder the noise. 
 How to solve the noise increase: 
 (1) If there is a shortage of oil, refuel in time at the connection of each moving part. 
 (2) If the rack installation is too loose, you can tighten the screws. 
 (3) If the fit gap between the shuttle and the shuttle is too large, the shuttle bed can be removed and the shuttle spring can be adjusted to reduce the fit gap. 
 (4) If it is caused by a collision between the cloth tooth and the needle plate, the position of the needle plate can be adjusted appropriately and then tighten the screw.