Failure Causes of overlock sewing machine and the Countermeasures(V)

Tight or loose upper bending needle thread of an overlock sewing machine 

1. The axis position of the upper bending needle is not adjusted properly, which is too high or too low; Readjust the axis position of the upper bending needle;

2. The upper bending needle and thread clamping plate is too tight or loose; Loosen or tighten the upper bending needle thread clamp nut;

Down bending needle thread tight or loose 

1. The position of the swing rod line of the lower bending needle is not adjusted properly, which is too high or too low; Readjust the axis position of the lower bending needle;

2. Under bending needle and thread clamping plate is too tight or loose; Loosen or tighten the wire clamping plate to a small amount of pressure, and there must be no excessive pressure;

Chain thread crochet thread tight of an overlock sewing machine 

1. The chain line adjusting plate is installed too close so that the output of chain line Crochet is not enough, resulting in the machine needle being pulled down; Increasing the output of chain Crochet;

2. The upper and lower positions of the chain thread threading board are not adjusted properly, resulting in the early or delayed outgoing time of the chain thread crochet; Adjust the outgoing time according to the standard;

Elastic joint material, resulting in expansion 

1. The surplus ratio of feeding teeth is too small, resulting in elongation; Move the differential wrench upward to the "0" position until the seam is flat;

2. The surplus ratio of feeding teeth is too large, resulting in shortening; Move the differential plate hand to the "0" position;

Machine weight of an overlock sewing machine 

1. Due to the impure nature of the oil; Clean the oil with gasoline, then fill in new engine oil and lubricate for several minutes

2. Because the parts are installed too tightly or the parts are inaccurate; Check and correct the screws in each part in detail to make the machine have a reasonable clearance;

 Oil leakage

The oil-proof plate of the feeding rack is broken or the cover plate is not flat; Check the oil cover plate or other sealing parts, and then replace the cover plate or other sealing parts;

Vibration 

The balance weight of the upper shaft is not adjusted properly; When changing the balance, when the needle is in the lowest position, the plane of the balance weight should be in the horizontal position;